Rules and principles - a long list of ideas that I like and try to apply in my life

À faire

Finish this page, written in a few nights in March 2021!

This page is inspired by the work of Bret Victor, mainly this inspirational video « Inventing on Principles » (see on YouTube: PUv66718DII). I loved his vision of living your life driven by principles, and fighting and standing for them. Of course, this idea is not his own innovation, and it has been the life principles of many of the most inspirational people (see my top 10).


I am Lilian Besson, professor of Computer Science at ENS Rennes, and former student in Mathematics and Computer Science at ENS de Cachan. I am a passionate programmer, an open-source enthusiast, and I did research for my PhD thesis, in machine learning, learning theory and cognitive radio. I also love to cook and meet people, to travel and exchange, to bike or hike, and I am chaotic-good even IRL. Welcome to my website.

For all the following sections and categories, I will try to sort some advices I can give, some rules I try to live for, some principles that I wish to defend, or ideas that I like and want to try to apply more in my own life.

This page, as most of the similar pages on my website, is intended for a personal use more than anything else. I will also try to give links to personal websites of inspirational people or authors, or great tutorials about various topics, if possible.


Please keep in mind that this page is a draft, and reflect my own personal point-of-view, not the ones of my employers, past present or future. This page will change, and in fact I would love if you contact me to show me that I’m wrong, that my ideas are not optimal or not good for such or such reason. Please contact me by email or other ways (e.g., open an issue on my AMA on GitHub).


Also, please keep in mind that ALL the content of this page should be read like every sentence started with « In my opinion, … » and finished by « … but of course I’m probably wrong, please do help me to change my mind and improve my ideas ! ».

This page is already quite long, and I do not intend on trying to keep it short, but rather as complete and detailed as I it can be.

Thoughts that I liked and want to discuss or include here

À faire

Regularly include some links to great articles here, and then remove the links from this list, to include them in the proper section(s) in my article(s), this one or others?

About limiting usage of social media, apps, online activity and smartphones (2021-03-29):

About social activism to fight the climate disaster:

  • « We can’t do it ourselves «, by Kris De Decker (2018). A long (~20 min) but very rich article, thanks Esteban for sharing it! I really liked this paragraph in the conclusion:

    A sustainability policy that focuses on systemic issues reframes the question from “how do we change individuals’ behaviours so that they are more sustainable?” to “how do we change the way society works?”. This leads to very different kinds of interventions.

About sponsoring open-source projects (2021-03-29):

Life philosophy

Top 10 rules and principles

I tried to summarize my main rules with just 10 points. Of course, it’s a partial list, and it will evolve. They will probably evolve, if I find a better way to write my ideas in a short sentence, or change my mind about some ideas.

  1. Always be curious and amazed, as the world is amazing in all its details ;

  2. When you spend money, you often can decide not to spend it. At least, you should try your best in understanding the consequences of this gesture (being social, economical, ecological) ;

  3. Be nice to everyone (except people who directly threaten your safety), don’t be afraid to defend your ideas, and be memorable (see below) ;

  4. You are not great for what you possess (and money is only a mean to achieve happiness), but how happy and positive you are, and for what you fight for, for what you believe in, for what you achieve ;

  5. Violence is never an answer nor a solution ; all form of war are bad and morally wrong ; using any weapon or form of violence to obtain anything from someone else should be considered as shameful and demeaning ;

  6. Never do anything that is offensive and illegal, or dangerous and illegal, or has negative impact on the world while being legal - but something that is not offensive and not dangerous, has no known negative impact but is illegal should probably be legal, so you should not refrain from doing it ;

  7. Go vegetarian (or try to), eat almost only local and organic and seasonal vegetables, fruits and cereals, and some cheese and dairy product as well as very small amount of locally produced alcohol ;

  8. Science has brought us where we stand, as a world-wide ultra-connected and ultra-reliable modern society. The 21st century is not the time to go back to obscurantism, and conspiracy theories ;

  9. Trust modern medicine (« western »), especially vaccines, our understanding of viruses and diseases, and the political measures such as masks and lock-downs that have been decided based on science ;

  10. Be exemplary in public (including Internet): anything you do, every behavior and action you take, when you are in public space and not alone, should be the best example you can give to other people, especially children, and posterity [1].

À faire

Try to summarize my life philosophy?

A visual summary of my life philosophy, and how I would like to be able to define myself, can be found in the details of this fun experimental business card I wrote as a Magic the Gathering© card:

Link to or

Inspirations for my life philosophy

Here I try to list some inspirations for my life philosophy:

  • My brothers and parents, uncle J. and grand-parents, who always have been concerned about respecting and living in respect of nature, reducing our carbon and ecological footprint, and who always encouraged me to pursue science and aim at culture and enlightment through discussions, philosophy, rational science, human connexion, and not obscurantism, conspiracy theory, extremist religious ideas, and selfishness ;

  • My closest friends, and more generally all the amazing people I met thanks to ecologist associations, board game clubs or bars, CouchSurfing and other (meeting people / dating) apps, and a lot of my comrades from my years studying in France, and colleagues from my years of research and teaching activities, in France, the UK, Switzerland and India. For a more precise list, see the acknowledgements in my PhD thesis!

  • Jedi philosophy, mainly Yoda and Obi-Wan Kenobi teachings. I am a strong believer of the value of Pacifism, and I refuse to admire military figures or « great warriors », because as Yoda says in Star Wars, « Wars not make one great » (in The Empire Strikes Back) ;

  • Open-source and free software philosophy ;

  • Civil rights and especially the 1789 declaration of civil rights in France (« Declaration of the Rights of Man and of the Citizen »), which despite being more than 230-year-old is still not applied correctly, in almost every country around the world ;

  • Jainism philosophy (in India) for their love and respect of all life forms ;

  • (Original) Hinduism, Bouddhism, and Christian philosophy of non violence, of respect, of tolerance, of universal friendship between all brother and sister humans ;

  • Dr Richard Stallman, founder of the free software movement and the GNU project, and many other activists and developers for their views and fights for free software ;

  • Tyler Durden, from Fight Club by Chuck Palahniuk (see some quotes below), and many other people including Middle-Age monks orders, for the will to possess as little as possible, and be great by your ideas and your actions not your possessions ;

  • Dr Jordan B Peterson, for many things about our modern society (including his views on patriarchy). I also like his view that « People don’t have ideas, ideas have people », and that most people are owned by the ideas they embrace ;

  • Estas Tonne, a famous guitarist, especially this inspirational video:

Voir aussi

This other page lists some quotes that I like, see quotes.en.html. TODO: start this other page!

TODO: detail more

Friends and family

  • If you want your friends and family to be able to help you, and if you want to trust them, then you should be trustworthy, help them, and be a fidel and trustworthy friend and family relative ;

  • Don’t be afraid to ditch toxic people from your life, especially wrongly-chosen partners or friends of friends, or colleagues.
    • It is harder for family members, but you can always try to have less frequent and less intense contacts with someone, if your relationship does not satisfy you.

    • It is also harder for colleagues, especially for your boss, but you can always ask to work with someone else, you have the right to change job if you’re unhappy there, etc.

  • When in a new city, don’t wait to meet new people.
    • It can be using CouchSurfing, « On Va Sortir » or even Facebook events, to meet locals for fun events ;

    • You have the right to go alone in bars, restaurants, and other social places, and try to meet people there. It’s easier in bars, especially bars that have games like board games, card or dice games, or exterior games ;

    • You have the right to ask a group of stranger friends to join them, even if you don’t know them, especially in bars or parks when a small group of nice or fun looking strangers are playing card games or games like French « pétanque » ;

    • You can even do that for people older than you, or slightly younger than you! Don’t ever try this for people less than 18 or highschool students, or potential students in University ;

    • You can also use dating apps or websites, like Tinder or OkCupid to meet new friends, or sexual or romantic partners if you want ;

    • Try as early as possible to be friendly and nice to your new colleagues (or comrades in school), and don’t be afraid to offer to meet outside of work/office, even on your first week!

  • Never be afraid of talking to a new stranger, if you are sure that you don’t annoy them in the process, and if you are ready to directly stop the interaction at the first hint of possible negative feeling on their part ;

  • Statistically, most people are nice and harmless, and therefore you should not fear strangers, regardless of what they look. Of course, trust your instinct and if someone does not inspire trust, be careful. If someone inspires negative emotions such as discomfort or fear, be on your guard. In most social situations, you have the right to stop talking to someone, to walk away for someone, to call for help or call the police if something is starting to go wrong.

About astrology and other non-sense

  • I am a strong believer of sciences, rational thoughts, and I do not believe in astrology. I laugh at horoscope, even if I keep good memories of reading horoscope for fun in 2009/2010 on a daily basis with some friends ;

  • If you ask me my astrology sign, I’ll reply that « I’m a Pikachu! »… you might answer, « but it doesn’t exist! », to which I would be forced to reply that « but none of the other signs exist either duh! ». Please don’t be offended. If you are, I guess we won’t be able to be friends, and I’m not sorry about it ;

  • I respect your beliefs if you happen to believe in astrology or other religious or non-religious beliefs, but please do not impose your beliefs on me. If you don’t want to hear about my rational arguments against astrology, then please accept that I do not hear about your arguments in favor of it…

Online communications

  • Disable any software that can indicate to your contact when you are logged in, like Facebook Messenger, WhatsApp, Discord etc: your friends should not be able to follow your activity patterns ;

  • I prefer to use email for professional stuff (coding, teaching, administrative work, research etc), and instant messaging for friends and fun stuff ;

  • I always reply to emails and any form of messages, even from complete strangers. However, if you call me for spam or advertising, I will be actively trying to make you remove my name and information from your database. I am lucky to not suffer too much from these annoying practices ;

  • I operate by Crocker’s Rules, so do not hesitate to speak plainly and frankly ;

  • The opinions are mine, especially on this website: I do not speak for my employers, either past, present or future ;

  • If you have a professional email that is not clearly firstname.lastname@company or @school, but something like kim876@... or then you should at least configure your email client properly so that your identity is added to your outgoing emails. I find it puzzling that many researchers include their short email (this kim876@... being a real example from a research paper) which do not allow to know their identity by just reading their email address ;

Concerning advertising

« Advertising has us chasing cars and clothes, working jobs we hate so we can buy shit we don’t need. [..] We’ve all been raised on television to believe that one day we’d all be millionaires and movie gods and rock stars, but we won’t. ― Chuck Palahniuk, Fight Club

  • I am of course highly against any form of advertising, especially against personalized advertising. It is responsible for scandals such as Cambridge Analytica scandals linked with Facebook. Being spied by YouTube is not perfect, but it allows the platform to recommend you better videos. Being spied by Facebook and Google (who log every click you make on any link) is already worse. But allowing these platforms to display ads that are tailored for you is not only invasive but also very dangerous, for you clearly but also your country, as we all heard of the scandals of Facebook ads and possibly Russian or foreign influence on 2016 and 2020 elections, all using the possibility for Facebook ads to be tailored to some population groups ;

  • I have been using ad-blockers on all my laptops since longer than I can remember, probably 2007 when my parents accepted to subscribe an Internet connection at home. I am certain to have always used ad-blockers, using AdBlock and then nowadays using uBlock Origin (see its website, its code), as it is the most light-weight and the most trust-worthy I am aware of (AdBlock had some dubious connections to advertisers who were able to pay to keep their ads in a « gray-list » that users had to disable manually) ;

  • I don’t think I make any brand or shop owner lose money by blocking ads, as I am simply (trying as much as possible to be) « immune to ads », and never decide to purchase anything from ads. I am a rational being: when I want or need to purchase something, I look into data to find the best solution (which in many case is simply to… not buy that thing!). I don’t let a 35s commercial advertisement influence my decision making process… and maybe you shouldn’t either!

  • I understand that advertising can be necessary for the survival of many websites, radio, and other advertisements, for now, but I don’t acknowledge that this model is the right one. The solution is to change the way these websites make money, not to allow ads, by increasing collaborative donations:
    • I am proud to have donated 60€/year to Wikipédia, which is able to run the 5th largest Internet websites with no advertisements (to quote a famous Sci-Fi movie « I’m doing my part! ») ;

    • In a movie theater, when you already paid 10€ to see a 1h30 movie, it is purely unacceptable to have to watch long advertisements. Watching trailers for up-coming movies could be acceptable, but advertisements for cars or other polluters is not. That is one of the main reason I simply stopped going to movie theaters (about 3 times / year at most until 2019, never since 2020)…

    • I have completely stopped to watch TV since 2009 and boycott any form of broadcast TV, for many reasons, one being that despite being non-free (even national TV are non-free, in France we have a tax of about 145€/year, that I refuse to pay), they are filled with annoying (and stupid) ads! If ads were realistic and smarter, I might find them less problematic, but most of the times, ads videos are just so stupid, and filled with stereotypes including sexist and racist stereotypes;

    • I almost don’t listen to radio because it has ads, and only listen to FIP (no ads) and Radio Classique or France Musique which has a low ads-to-music ratio and not so much « bad » advertisements (but they both have ads for cars, for instance). If I could pay 5€ a month (or a small reasonable amount of money) to have ad-free versions of these French public radios, I would gladly pay! Unfortunately, even if you pay the 138€ yearly fee from French taxes, you still suffer from ads! So that is the reason why I don’t and won’t pay this tax ;

    • I hate the fact that advertisements are so frequent in urban environments, from buses and bus stops to large advertisements panels, and including shops and some restaurants. I will clearly never buy from any large (or already rich) brand that does advertising in public spaces ;

    • The only exception to advertisements in a city are for advertisements for local (i.e., non (inter)national brands) shops, bars and restaurants, public services and public news (but not to hire for the military!), and cultural or social local events ;

    • I hate that public buses and supermarkets play radio that have ads (or sometimes just ads, for larger supermarkets). This is one of my main arguments in favor of public train services (no music nor ads in any train I ever took in Europe), and organic shops and grocery stores (such as BioCoop and « Day by Day » in France) and tiny French bakeries.

  • On the one hand, I don’t like that many YouTubers I follow for years now need to include promotional content in their videos. I simply skip the 1min or 2min talking about the product, and I will never buy or give money to brands that need these sponsoring (except maybe NordVPN). On the other hand, I like to sponsor directly these YouTubers by donating money monthly, on Patreon and Tipee (French platform), see what-i-watch-on-youtube.en.html ! I donate between 30€ to 50€ a month, to various creators of music and videos! I would consider buying a subscription to YouTube premium, if it wasn’t owned by one of the largest company in the world (Google), which is also one of the companies with the largest growing rate. They don’t need my money, and don’t need yourse either!

  • The more I see any brand using advertising, the less I want to buy anything from these brands. This is especially valid for the entire car industry, alcohol and cigarettes industries, and for world-wide food or « restaurants » brands such as Starbucks, McDonalds’s etc (regardless of their terrible moral and philosophy, and huge ecological footprints). The simple fact that some brands advertise so much is a bad sign. For instance I grew up watching lots of Disney movies (which I still watch), and I love Star Wars (see star-wars.en.html, but I stopped considering to pay for watching Disney+”s The Mandalorean show, when I saw they were advertising it in the streets of Rennes! Similarly, if I were to watch such TV shows, I would feel no shame in downloading these from illegal platform, knowing that Disney and other large companies make billions of dollars of profit every year. They clearly don’t need our money!

  • You should do the same: the more you see or hear a brand using advertising, the more you should disregard this brand (I first wrote « hate » this brand, it might be too a strong decision for you) ;

  • I am also strongly opposed to personal tracking online, and even though I used Google Analytics on this website (and others) for years, I am no longer doing so, and will try to remove these trackers from any documents I own online. I feel ashamed of having used Google Analytics, especially because I was aware of its evil nature from the beginning. I have no excuse, except the fact that it’s easy to use, and fun to have insights about the visitors of your website (see stats-google-analytics.en.html) ;

  • I have been using other browser extensions to prevent these evil websites from spying me, such as No Script, Ghostery, and more. See firefox-extensions.en.html for more details ;

  • You should use the Mozilla Firefox browser, and not alternatives coming from large companies such as Safari from Apple, Internet Explorer from Microsoft, and Chrome from Google (or at least use Chromium). From 2019, Firefox has built-in capacities to block personal trackers and other dangerous scripts, while being the best browser in almost all aspects ;

Voir aussi

If you have a Raspberry Pi at home (or a GNU/Linux computer), and you want to completely block ads on your local network, including on smartphones connected to your Wi-Fi, you can install Pi-Hole.


  • Advice and life philosophy: Learn how to use all the major « numerical » technologies, they will be here for a long time ;

  • Even if you are (like me) a huge geek of numerical and computer-based technologies, don’t neglect how important are « old school » non-numerical technologies, like mechanics for bikes, material for cooking and agriculture, etc ;

  • When receiving any new technology, you have to be curious! Try to be a smart user of any technology you use, be curious about how they work (not only computer stuff), what are their fundamental working principles (e.g., microwaves oven), their limitation, their history (years of discovery, first manufacturing, global public adoption, etc). How will they be recycled if they break? Where and how should you dispose of them, if needed? Can you fix them if they break?

  • As for any other things in your life, you should not buy anything that is not needed. Technology and especially machines and computer and « numerical » devices, such as smartphones or « smart-watches », have a very significative ecological impact on our world, as they require rare metals and rare earths to be produced ;

  • The same curiosity should apply to every object that you encounter regularly in your life. We tend to acknowledge only modern numerical technologies as technologies, but almost everything we use are technologies, that have their own history, industry, and amazing things that you can learn and discover about them. Do you know how light bulbs works? And your keys and doors? Your kitchen and cooking pans? Do you know when was invented or how was produced the glass used in your windows? And where were produced your eye glasses? How do your laundry machine and laundry powder work? (see below for laundry)

  • The same curiosity should apply to everything, even outside of your home. You can be curious about the manufacturing process, history of development, and social and technologies aspect, of everything, including urban elements (parks, side walking in the streets, etc), intellectual and artistic creations (like poetry, music, movies), social behaviors (e.g., do you know the reason for hand-shaking?), social constructs and institutions (like notaries and rental agencies) ;

  • Any object that uses a battery should be regarded as highly non ecological, as something we should avoid to buy and be extremely reluctant to accept, and anyone who claim that a battery-powered device has zero carbon footprint as a lier, and possibly an evil person if she/he should know better. Lithium is the key ingredient of modern batteries, including the tiny ones in our phones and laptops, medium-sized ones in electrical bikes or kick-scooters, and larger ones in electrical cars. Lithium is almost never mined by adults and free workers, but too often by kids, slaves or workers in work camps, in China and other countries which violate human rights and do not provide safe work conditions for their workers. That’s why I strongly refuse to switch to an electric bike (see below for more details about bikes and kick-scooters) ;

  • I find « smart » watches to be a stupid product and hope they die and don’t spread more: seriously, just bye a 16€ Casio watch, and use your « smart » phones for its purpose. It’s already a shame to be part of such a polluting industry by owning smartphones, we should strictly refuse to accelerate the process by also buying a polluting so called « smart-watch ». The only smart-watches I can consider acceptable are Casio calculator and/or radio watches from the 1990s ;

  • I find our dependance to smartphone frightening. When I remember my life before 2011 when I didn’t own a smartphone, I am sure that I would like to go back to « simpler » times with no smartphones. Smartphones are extremely advanced numerical technologies, far more powerful (in terms of computational capacity and sensors, and global capacities) than anything we had before the 1980s, and are among the most amazing tools ever produced by humans. But they also are very polluting to produce, and very hard to recycle… For these reasons, we should aim at keeping our smartphones as long as possible, and buy them from second hand only! Keep in mind that most of the carbon footprint of a smartphone comes from its manufacturing and its transportation, not its electricity consumption to recharge it, wireless communications (which have large footprints on their own) and global usage. So if you buy a smartphone from second hand, try to keep it for many years, and recycle it correctly when it dies, you already do more than a large part of humanity, who buys new smartphone every couple of years and don’t recycle them!

  • Most certainly, I will never a smartphone again if mine breaks. If I ever « have to » buy one, I will only consider buying a FairPhone (or equivalent or better products). As of April 2021, the FairPhone 3 costs around 400€ for a high-quality and reliable, long-duration and reparable smartphone: that’s the best solution.

  • TODO: more advices, and more of my « rules and principles » on technologies?

Voir aussi

My favorite computer tools are there in another page, and favorite Android smartphone apps are there in this second page.

Concerning renewable energies

  • I am of course a strong believer of the power of renewable sources of energy, like wind turbines, solar panels, geothermal power plants, and other alternatives to nuclear power and fossil energy ;

  • I have changed my personal electricity provider from EDF to Enercoop in 2020, and even if it increased a lot my electricity bill (I didn’t count very rigorously, but I estimate between +25% and +60% between different months), I am very happy of this decision ;

  • However, contrarily to many ecological activists, I am in favor of nuclear power, until we can be freed from fossil energy based on gas, petrol and oil. Of course, nuclear power plants pose the problems we know: any accident can have dramatic consequences (hello Chernobyl and others), storing nuclear waste is still a major problem, and mining Uranium is difficult. Uranium mines have the same problem as lithium mines, but the same problems concern coal mines! As this XKCD strips shows it, uranium is just so rich in energy that we should adopt it, for no, until we can find a better solution:

Full energy density, in Mega-Joules by kilogram. Uranium is just so rich in energy that we should adopt it, for no, util we can find a better solution.
  • I am tired to read too regularly that renewable energy sources like wind turbines and solar panels can have « zero carbon footprint », as it is simply scientifically wrong. How do you manufacture the turbines and the panels? How do you transport them to the production site? How to transport the produced electricity without large copper electric wires, local transformation units, and many other production units, that all have a cost to be built and maintained? The best example is solar panels, as manufacturing them require rare earths and rare metals, which require mining in extremely hard conditions. Mining and extracting these materials cost energy (usually from coal, as these mines are mostly in Africa, Brazil and China), workers that need to be fed and transported, and transport from the other side of the planet. Even the most modern solar panels have a life expectancy limited to at most 15 years, and in average they will not last that long. They have to be replaced more often than other heavy production solutions (including nuclear power plants) ;

  • What is true, however, is that specialists hope that these renewable energy sources have a much lower ecological impact (including their carbon footprint but also other measures) that fossil energy such as gas and oil. Solar and wind energy _are_ renewable, and if we manage to produce wind turbines and solar panels in a green process (or at least do our best), and with higher efficiency rates, then they will indeed be our best bet for the future ;

  • In the meantime and while we wait for these desirable innovations, as long as Uranium is available it will remain the most efficient energy source (by such an incredibly large factor, that it seems impossible to understand the difference in the two), and so it will remain the energy source we should globally adopt. On the global scale, the most efficient and fast and easy solution to reduce carbon footprint and released quantity of greenhouses and toxic gas by the world-wide energy production would be to stop coal and gas and oil factories (in China, Germany and Europe, USNA and all around the world) and replace all of these strongly polluting factories by nuclear power plants, rather than trying locally to enforce individuals to set-up solar panels on our roofs and wind turbines in your gardens ;

  • As an individual, of course you can look into purchasing such small wind turbines or solar panels, to install on your home or in your backyard or land. But just because they will produce energy from a renewable source (wind, sun) does not mean that this energy source that you can use at home will be renewable! Solar panels and wind turbines require manufacturing, as I said, and maintenance. Except if you take into account the whole life of these new purchases, and have scientific data to backup the unverified claim that they will reduce your global ecological and carbon footprint, you have no good reason to do so ;

  • At least, you have no good reason to do so for the sake of ecology (except if you have data saying otherwise), but you might have other reasons. You can aim at being able to produce all or part of your electricity for your home for other reason, one being autonomy and independence from larger electricity providers, from your governments etc. If that’s your goal, keep in mind that most of these « renewable energy » sources will not last more than 10 years, and they are very fragile, highly complicated technologies that can break anytime (from a small tempest, a heavy rain or snow), and require expensive maintenance and purchases to extend their lifetime or to replace them. This will most certainly change and get improved in the upcoming years, but I have no hope that we will soon have solar panels strong enough to survive longer than a human average span life.

Concerning computer or laptops

  • Keep your computer up-to-date, especially for the operating system, and all software that you use to connect to Internet ;

  • Your brain is the best anti-virus, and you best tool to protect yourself from spam and scam and piracy ;

  • Never open a link without looking at the domain name and the address. If you use Safari or other shitty web-browsers, at least activate the option to see in the status bar the links before clicking them… If you use Mozilla Firefox (and you should), you can check-out this page firefox-extensions.en.html for ideas and suggestions about good extensions to improve your user experience and help you protect your privacy online ;

  • Configure your laptop to not connect automatically to any Wifi networks ;

  • If you have enough money, consider subscribing to a VPN (Virtual Private Network), such as NordVPN which seems to be one of the most trustworthy and reliable offer on the market. If you subscribe for 2 years, it can cost around 3€/month, which is not a lot of money for a lot of advantages: it’s the price of two coffees (in France)! Most surely your body will appreciate if you reduce your coffee consumption by two coffees, and your privacy and Internet use will get better with a VPN.

Concerning Smartphone

  • Keep your smartphone up-to-date, especially for the operating system, and all software that you use to connect to Internet ;

  • Never keep your location activated, except actively when using an app that requires your location for good reason (like Google Maps). The same goes for Bluetooth!

  • I always put my phone in airplane mode when sleeping: my sleep is more important than the external world. This might not be applicable to you if you have kids or parents or relatives that you feel responsible for and who could need to be able to join you at anytime.

Back-up for your phone or computer

  • You should always back-up for your phone or computer, regularly, on different hard-drives, at least two ;

  • If you back-up some important document to a pen-drive or USB stick, don’t keep it in the same bag as your laptop! If it gets stolen or you forget it somewhere, you’ll loose your data and your back-up!

  • You can use on-line services to back-up some folders, like Dropbox, Box, Microsoft Skydrive, or Google Drive, that are free, or pay for some services ;

  • Nobody reads the condition and terms of utilization of any web-service, but there have been proofs of cases where young startups were disabled by Google after some documents were uploaded to Google Drive, so you can safely bet that the company hosting your files actively read ALL of their content, and can steal ideas as well as private information, and resell it to other companies (such as advertisers, see below about ads) ;

  • If you do use such on-line service, you might consider using an local encryption software, that can transparently take care of encrypting the files before sending them online. That way, Dropbox or the company has no way to access your data. See this list, and good solutions appear to be Cryptomator and Boxcryptor. These software should be free and open-source (remember that open-source usually mean more trust-worthy, especially for any encryption software) ;

  • Since 2015, I have been using a ownCloud (which is a free and open-source software), locally on all my laptops, which is syncing some files and folders online, on a web-server. It is very reliable, and I have used it on a daily basis for 5 years, with up-to 10 GB folders, without every losing any data. It works much better than Dropbox that I had to use for my first research internship in 2012!

My thoughts on non-open source software

  • In one line, my philosophy about closed-source or non open-source software is: ban them, fight against them, hat them ;

  • In your personal life, it is surprisingly easy to ban most of the non open-source software you use on a daily basis:
    • On your laptop, just use GNU/Linux and do not intall any closed-source or non open-source packages ;

    • On a smartphone, it’s harder, but you can use F-droid to install only FOSS (Free and Open-Source Software) apps on your phone. However, you will miss most of the apps by large companies, such as the CouchSurfing or YouTube apps ;

    • On both, the main problem is that we are more and more relying on websites, web-apps and « cloud » services, for almost anything, and these will never be trully open-source, and almost all of them are entirely closed-source and privately-owned. Examples include Skype, MS Teams, Discord and Zoom for visio-conferencing (see my page about Jitsi as the best alternative), Messenger and WhatsApp for messaging, etc ;

  • You can easily convince your friends, family, students and colleagues that they can do like you!

  • One notable exception are video-games. Of course, there are lots of great open-source video-games, but none of which are as awesome and great games as my favorite games from the last 20 years (see top 10 <top10.en.html>), like Bethesda’s Skyrim or CDRP’s The Witcher 3 ;

  • The argument of many video-game enthusiast to stick to a Windows computer is now almost gone to dust: the playOnLinux, Steam on Linux and Wine projects bring almost every Windows-only video-game to any recent GNU/Linux computers. Of course, part of their source-code is not FOSS, but at least your main OS and the rest of the softwares used on your computer can be!

My thoughts on open source software

  • The exact opposite philosophy, in comparison to non-FOSS software: you should adopt them, love them, and take part in their development if you can and have time for it !

  • You have the right to check out the code of any open-source software, so try it!

  • You can contribute to any open-source software, and if you do contribute and you are not warmly welcomed in the community of this software, you can (and should) consider to stop using it ;

  • You can contribute even for changing one line, one word, one letter in the code or documentation of any open-source project, and in fact, if you see a typo anywhere in an open-source website or software, it’s your responsibility to notify the developers and try to fix the mistake yourself! I do this a lot, for instance I changed a few times one letter in OCaml documentation.

Web and online documents

  • If you produce technical content, regardless of its nature (science blog, technical articles, etc), don’t you put it online behind a paywall, such as Medium ;

  • If you produce content, such as photos, don’t host them online behind a paywall, and also always keep local back-up of your production. If your entire photograph career is built on your Instagram profile, you have to be aware that Facebook can shut you down in one click…

  • Anything that has ever been accessible on a website is online forever : Google and Yahoo and Bing crawlers are incredibly fast, Microsoft and Facebook and Twitter most probably aspire and copy the data behind any links you paste in any of their service, etc. Even if you own your website, and you upload document a.pdf, delete it the next day, you have no warranty that Google bot hasn’t already cached your document (which they do for evil purposes and to improve their search engine and offer a cached version of website), or that it hasn’t already been archived on or any other online archive ;

  • Don’t upload any documents you don’t have rights on, especially electronic copies of books or music, photographs of public building, persons etc ;

Your photos

  • Before you upload one photo of yourself anywhere, even on « private » servers like emails or Facebook messages, you have to understand that this photo will be online forever, and that the person you send ;

  • The same applies if you upload a photo on a public server, like a Facebook or Instagram profile picture, except now anyone on the planet can do these things ;

  • As soon as one of your photo is publicly available somewhere online, you need to know that now anybody can recognize you in group photo, in a crowd, in the street etc. It is not a major threat to your life or privacy, but it is a threat and a risk, that I do not want to suffer from ;

  • Never upload the photos of anyone else, or a photo of yourself with other people: even if they give you the right to do so on day 1, maybe next month or in 10 years they would want their picture to be deleted, and you most probably will not be able to do so.

  • Tips: if you need to send a picture to someone, add a unique watermark on it (e.g., « sent to Superman on 2021-03-17 at 21h45h12s, by Facebook Messenger »), and on different parts of its metadata, so that if this picture is directly leaked with no modification of the watermark and metadata, you will know who is responsible. The same precaution is even more valid if your picture or video is naughty and you really don’t want it to become public ;

  • My rule has always and will always be : never upload a photo of myself anywhere on the Internet ;

  • And never send a picture of yourself to anybody, except maybe very close friends or family, using end-to-end encrypted messages or one-time paste-bin from my own OwnCloud instance ;

  • I will aggressively react against anyone who uploads or uses a photo of myself online, even in « private » use like in emails or Facebook messages. I will go as far as suing you, if you do that and refuse to delete it as soon as possible ;

  • I will never allow for a picture or photograph of myself to be released in public, especially not on YouTube or Facebook.

Your voices

  • With the increasing powers of « deep fake » technologies, one could be worried about the risk of using publicly available samples of one’s voice (e.g., in a video lecture you uploaded to YouTube) to forge a model of that voice, and then use it to scam your friends of family, or steal your identity ;

  • If you feel concerned about these risks, the simple solution is to: a) never upload a video (even with no webcam or image) of yourself speaking to any public website (especially Google’s YouTube), b) never allow the recording of any of your public intervention in scientific conference or other things ;

  • If you feel concerned but you already leaked some content of your voice, I guess you should: a) delete these sound extracts, b) try to hunt all of them down, c) ask your friends whom you sent voice messages to delete their files and attachments from Messenger and WhatsApp etc ;

  • If you feel extra concerned about you, be careful when answering your phone from an unknown number, especially at late hours, it could be someone calling you just in order to get a long-enough recording of your voice, in order to later forge a model of your voice and use it to harm or scam you.

I think I am almost as concerned about this potential threat as my last bullet point suggest, but not yet willing to be paranoid about it.

Your videos

  • I guess the same things apply to your face and body images and videos, combining my points-of-view on pictures and voice ;

  • I will never allow for a video of myself to be released in public, especially not on YouTube or Facebook.

I am extremely concerned about this aspect, and I am proud to have been able to work as a researcher for four years and as a professor of computer science since 2019, while refusing to have any videos of my lectures or scientific presentations recorded in public.


Coronavirus crisis

Voir aussi

More details about this crisis and how it affected me, and my teaching, can be found on this page: coronavirus.en.html.

  • I wash my hands before exiting home and when coming home, before/after eating or going to the bathroom, and before/after any class ;

  • I no longer eat or drink in public if I can avoid it, and in a bus or train I never remove my mask, for any reason ;

  • I always wear a mask when I’m not at home, in the street, at friends, in my University, in the bus, in stores, etc. I try to change my mask if I wear it for more than a few hours ;

  • I only wear surgery masks, and usually take a new one every day when I go to work or buy things or walk in my neighborhood. I estimated at less than 45€ the money I spent on masks between March 2020 and January 2021 (I don’t go out very much!) ;

  • I refuse to enter a shop if the owner or someone inside has no mask ;

  • Most probably, I will consider you as stupid if I see you not wearing your mask correctly in public, especially it you wear it only on your mouth and not your nose (or the other way around), or under your chin while drinking, eating or (even worse) smoking!

  • I now also refuse to enter a bus if the driver does not his/her mask correctly, or at least I try to talk to them. I have already notified Star, the Rennes transport organization, about insults and threats I received (twice) from drivers, when I was politely asking them why they had no mask on. I will continue to do so: as publicly highly visible workers, they have to give the best example.

Money and how to not spend it

> « Reject the basic assumptions of civilization, especially the importance of material possessions. » > ― Chuck Palahniuk, Fight Club

  • Act as a responsible consumer: what you buy has an impact ;

  • Every cents and euros (or dollars or whatever money) you spend on anything has an impact ;

  • Don’t buy something except if you really need it ;

  • When buying or spending money for presents, you have the right to prefer to not offer a present rather than buying something useless. You can also offer services (like tickets a culture event, a massage, movie tickets etc), rather than material goods ;

  • Never spend any amount of money before taking the time to know to whom it will go, and for what it will be used ;

  • If you buy something from a new shop, a new bakery, a new bar, a new restaurant etc, before you accept to spend any money there, you should try to be curious about the shop. Where do they buy their beer, who owns the shop, where is made the t-shirt you are looking at, where goes the 20€ for this CD, etc. If someone in a shop refuses to be open about these details, maybe you can just take your business elsewhere. It is especially true for bakeries and any shop who sells food: you have the right to ask for lots of details (what kind of flour, where was it produced, how many employees work here etc) ;

Voir aussi

See other paragraphs about « Alimentation and food », « Technologies », and « cars » (below).

About money not being a goal


  • Money is a mean, a purpose, to achieve three goals:
    1. survival, by buying the minimum amount of food and water, having some clothes and a shelter ;

    2. personal happiness, by buying more food that you like, other beverages than water, more clothes and a place that you can call home, and other things. Other things include cultural activities such as theaters and concerts, cultural goods such as books and such, sports such as a good bike, transportation, etc ;

    3. and improve moral and good things in the world, by helping to bring 1st and 2nd goal to as many people as possible ;

> « You are not your job, you’re not how much money you have in the bank. You are not the car you drive. You’re not the contents of your wallet. » > ― Chuck Palahniuk, Fight Club

Alimentation and food

Except if you really are low on money, you can live and sustain yourself without buying and consuming meat and fish, and without buying anything that comes in plastic and non-recyclable wrappings.

TL;DR: TODO: summarize my position on alimentation and food.

  • Go vegetarian, seriously. Or at least, you should consider reducing drastically the amount of meat and fish product that you buy. Or at least at least, buy twice as less but twice as good and twice as expensive meats, aim at locally produced and ecological and biological meat. Chicken and birds meat (ducks etc) have lower impact and ecological footprints than pork, which has lower impact than « red » meat from cows. In my opinion, all meat should be banned progressively and slowly removed from our alimentation, all over the world, but the priority is on cows and porks ;

  • I don’t really care about the impact of this change in your diet on your health, even if it can have some positive impact, but I care about the ecological costs and moral implications of consuming meat and fish, and you should care too ;

  • Don’t buy meat and fish, and living things in general (even if they’re dead when you buy them) ;

  • If you would not be willing to kill yourself the animal or animal piece that you just bought or ate, how come you accept that someone else killed it for you?

  • If you consume a lot of dairy products like milk, cheese, yogurts and ice-creams, you should know about the ecological and moral costs of having animals (mostly cows) in farms. Most milk cows are raised only for milk, but they are inseminated artificially, and you should read this as it is: cows raped regularly using huge mechanical machines, with no consideration for their pain or well-being ;

  • I could be mistaken, but if you buy organic (bio”) eggs from a local farm, and not too much, you’re fine. Chickens don’t need to have a cock around and to be fertilized to produce eggs, and if they live in a small farm and outside and in a good environment, from what I read, they are pretty much as happy as possible ;

  • There are eggs or milk products in almost any pre-processed food, as well as worse products such as palm oil, conservatives, colorants and more, so read carefully the labels before buying anything ;

  • Don’t buy anything that comes from far away if a local alternative exists, and try to remove anything that comes from far away. I haven’t bought bananas or pineapples since a few years, and I don’t miss them!

  • Even exotic products like kiwi, rice or oranges can be bought locally (France produce each of these in pretty large quantities) ;

  • Ban palm oil from anything you buy ;

  • Reduce as much as you can your consumption of products grown far away, including tea, sugar, coffee, chocolate and non-seasonal vegetables and fruits. You read me right, I advertise and would like to fight for reducting our consumption of tea and coffee, and also chocolate, despite being a long-time enthusiast consumer of such products, I also consider them as drugs (see below about drugs). These three products are among the most heavily-produced and heavily-consumed products on the planet, they always come from far way if you live in Europe or North America, and they have a large ecological and economical negative impact ;

  • Don’t buy any fruit or vegetable that is not from the current season, or only sparsely and occasionally. In 2020/21, I did buy like one or two tomatoes between October and June, when I really wanted a fresh tomato in the winter, and even if it’s not perfect, it’s not as bad as buying any vegetable anytime, and it stays exceptional (and I aim at local producer). You should be aware of this, and try to minimize the exceptions ;

  • Of course, the same rules apply when you don’t cook and eat at home, including if you eat at your family’s or friends” place, your company’s cafeteria, restaurants and bars, etc. The simpler rule is to minimize the number of meals you don’t cook yourself, as most of the times restaurants use non-seasonal, non-local, non-organic and low-quality products. It is especially true of cheap street food places like kebab places or bakeries selling sandwiches, non-organic and non-vegetarian restaurants, and student/campus restaurants (« resto U » in French): if you have enough money (and time) to avoid these, your best option is always to cook the day before, and bring your lunch box!

  • If you use lunch box, you should buy once a good quality glass lunch box, like a Tupperware (but there exists locally produced brands), that don’t pollute your food with plastic particles when you store hot food from your pot/oven in the lunch box, and when you re-heat it. In my case, I bought a plastic lunch box in 2016 but lost it in 2019, I also bought a ~15€ glass box in 2017 and I use it on a daily basis since then. I received as a gift a « bamboo-produced » eco-plastic lunch box in Christmas 2019 (thanks Marine) and I use it very regularly too. I no use any plastic boxes, and I don’t see any positive arguments about them, in comparison to the two alternatives of glass or bamboo lunch boxes.

  • You can also use these lunch boxes to buy some food directly with no wrappings: bakeries should not refuse to serve a few cookies in such box, cheese shop can use them too. In Rennes, I buy my cheese at « Fromagerie Gauthier » in La Criée central market and they are always very nice and comprehensive of my refusal for useless plastic/paper wrappings: they have accepted to use my boxes every time since 2017 ;

  • You can use small cotton bags, either home-made or bought in BioCoop (or other ecological/organic shops), to buy lots of products with no wrapping, including sugar, flours, cereals, muesli and other dry product (lentils, pastas, rice etc).


Like for other consumer decisions, if a shop owner or employee refuses to accept your request (e.g., of not using any one-time or polluting plastic or paper wrappings), and he or she is unwilling to listen to your (rational) arguments, then you should take your business elsewhere: remember than the easiest militant choice is to refuse buying and spending money for things you don’t accept as morally and ecologically correct.

About drugs

TL;DR: I’m trying to completely stop alcohol, despite my long-time liking of beers and wines. I am fighting against cigarettes, and against all sorts drugs.

About alcohol

TL;DR: I aim at completely removing alcohol from my diet, and I have never been a heavy drinker and almost never drunk in my life. I love beers and wines and cocktails and home-made digestive, but I try to drink as little and as infrequently as possible (once a week or once a month), and you should do too!

  • Yes, alcohol is a drug. It is actually recognized as one of the most addictive drug on the market, and it is directly and indirectly responsible for hundreds of thousands of deaths every year, in almost every country on the world, far more than terrorism or (recent) wars ;

  • Yes, you can live without it. Yes, you can have fun without it. And most probably, you should drink less ;

  • Yes, you have the right to host a party or a dinner with friends or family with no alcohol. If anyone gives you a hard time about it, don’t let them tease you, stand up for yourself and explain your position. If they don’t like it, maybe they shouldn’t be invited next time, and they can also leave right now! It happened to me, and will most surely happen again, I’m not afraid of it ;

  • TODO: write more?

  • When buying alcohol, even low-degree alcohol like beer or wine, follow the same rules as for any other kind of food or products: only buy from your own country, aim at the most local things (the only beer I buy since a few years are all made in Rennes or Cesson-Sévigné, less than 5 km away from my place), and buy as less as you can ;

About cigarettes

TL;DR: I am and have always been actively against cigarettes, smoking and tobacco. I dream of a society who would ban cigarettes and tobacco world-wide, and fight against it as harshly as against cocaine and heroin.

  • Just don’t smoke, don’t try, don’t buy cigarettes ;

  • No but seriously, don’t ;

  • Your smoke is poison and is toxic to anybody, don’t force it on people ;

  • Despite what many people think, it is forbidden to smoke in any area of a public bus or train station, if it is outside near the station platforms. I had and will continue to relentlessly fight against this uncivil gesture, and I am proud to have the gusts to annoy you if you do smoke there. It is one of the area where cigarettes are the most not correctly thrown in garbage bins, and this is outrageous ;

  • I tend to be much more reluctant to give money to homeless people if I see that they smoke or have cigarettes. I also tend to be much less nice and helpful if someone is smoking in public ;

  • If you do smoke, please respect at least the following rules (which are in the French law!): don’t smoke inside bars, restaurants, public transport such as buses or trains, and even outside in the streets or parks, don’t smoke close to people and especially children ;

  • If you smoke and do not throw away your cigarettes in a bin, or in a personal box that you keep for this purpose, then you are a) stupid, b) a pig, c) responsible for the up-coming pollution of up-to 500 liters of clean water (yes, 500L with just one cigarette butt), d) you should pick this cigarette up and throw it correctly ;

  • I had and will continue to relentlessly fight against this uncivil gesture, and I am proud to have the gusts to annoy you if you don’t dispose correctly of your shitty and dangerous butt cigarettes. In France, this is illegal and can cost you up-to 135€ fees. I am sadden to know that police forces don’t really care about this outrageous « detail », and never act against this. I don’t have statistical data on this, but would like to have more ;

  • There are bars in France where owners let the clients smoke inside (and they smoke too): it is illegal, outrageous, and quite insulting. In Rennes, such bars are the two closest bars to my place: Le Marquis de Sade located rue de Paris (where I went once for a (very nice) concert, but I should not have supported this illegal practice), and Le Synthi rue de Chateaudun. If I still live there and they open again after the coronavirus crisis, I will probably try to report this to the local police. Do you think it would be wrong to do so? Please reach out, and discuss about this with me, as I said in the introduction, I have strong opinions but I would love nothing more than be changed my mind and proved wrong about any of these opinions ;

  • Do you realise all their negative ecological and economical impact that your smoking have on the world? Producing cigarettes requires to grow tobacco, on lands that could be used to grow vegetables, to dry it and then transform it in cigarettes (by worker who could cook delicious meals using said vegetables), they also need papers who could be used to produce books, and then fuel and gas to transport them from the other side of the world (spoiler alert, tobacco don’t grow in organic farms in your neighborhood!). While you smoke, it destroys your throat, teeth, lungs and hair, and it does the same to your kids, friends and neighbors, and anyone who unluckily breath your smoke-of-death. Buying packets of cigarettes also produces wrapping and waste. The last and worst part is about cigarettes butts. So many of them finish in the oceans and rivers, and pollute clean water and destroy local and world-wild wilde life. But even if you throw away your cigarettes, in garbage bins, they are simply burned as there is no way to recycle such toxic waste. So all the toxic compounds (that partly poisoned you already) finish in the atmosphere…

  • TODO: write more?

  • Summary: if you smoke and are not aware of all this, and are not actively trying to stop, most likely I will consider you as stupid. I will try to explain this quickly if I have the chance, and if you don’t change your habits, then there is no chance for us to be friends, and I’m not sorry. If we are forced to be colleagues, I will of course do my best to work alongside with you, but you already lost part of my respect, and I’m not sorry. Be sorry for your negative impact and your toxic habits!

About recreational drugs

By recreational drugs, I consider any substance such as weed or cannabis used for fun and recreational purposes, and cocaine, heroin, meth, poppers etc.

  • Just don’t ;

  • No but seriously, don’t ;

  • All what I wrote about cigarettes above can apply to most drug: they are extremely bad for your health, for the environments, they are almost never produced in clean and respectful environments, and you cannot trust anyone who is selling to you an illegal substance on which you have no control ;

  • Actually this last point is one of the thing that always puzzled me the most about any illegal drugs: how can you trust someone who hides this substance in their socks, and who hides from cops, that they are indeed selling you the thing you want to smoke/consume? And if you think a little bit more about all the steps that this piece of drug had to travel before arriving in your possession, how can you willingly accept to take part and finance such awful things?

  • A good rule of thumb is: if it’s illegal to buy or possess, it’s illegal to buy or possess. Easy right? So just don’t.

  • If you are suffering from an addiction to such a drug, I am aware of how difficult it can be to stop the addiction. You can find help, there are free hotlines to call to search for information about fighting drug addictions, and you are not alone in this fight. You can succeed and fight yourself out of this toxic habit!

  • Are you bored? Read Wikipédia, read a dictionary, talk to people, play video-games, listen to music, and many more activities that are virtually free (not like drugs), harmless (not like drugs), legal (not like drugs), and much fun!

  • TODO: write more?

  • Yes, I am aware of the possible health benefit and positive effects of medical cannabis. I guess I’m not against that, but this section is entitled « recreational drugs », not « medical drugs ». My position here lies with the one of my government: as long as it will be illegal to buy such product, I will be against it.

House and interior life

  • Since 2012, I have chosen to follow a very simple rule: both my professional and personal addresses are publicly available on my website: on this callme.en.html page, and my CV. My reasoning is the following: if someone wants to find your address to come and hurt you, or steal from you, or any other form of aggression, their purpose is negative and evil towards you, and most surely they will find a way to find this address (either by following you, by calling you, your family, friends or your employer and using social engineering to hack into this person and make him/her reveal private information). I know how easy it can be for a thief to obtain someone’s address if he or she is willing to lie and cheat, so I believe that the benefits of publicly displaying my address are greater than the risks. These advantages include: I like having an URL with an anchor that I can type from memory (in English, in French) so I can send my address (along with an embedded map of the local neighborhood, curtesy of OpenStreetMap) in an email or direct SMS message ; I like the fact that a friend who would want to send my a postcard can just search for my address on her favorite search engine ;

  • I like to be open about this. However, I am cautious not to give my private Digicode to anybody, except close trust-worthy friends, and if someone calls me or rings my doorbell, I am usually very cautious and won’t open unless I have some reasons to know that I’m safe to do so. You might have to be more cautious than me, depending on where you live, and how secure is your home, house or building ;

  • I apply a very strict view of « My home, my rules » (domus mea praecepta mea in latin): if you come visit, even for a short time, follow my rules at home, or simply don’t come (that is one of the reason of this page). If we get into an argument because you did not respect one of my rules (e.g., you smoked inside, you got offended because I don’t serve wine or beer, or anything else), I can and most probably will ask you to leave, no matter the hour ;

  • I don’t wear shoes inside my home, or anybody’s home, I know that in USNA it’s customary, but it’s just stupid and not hygienical: your shoes bring back every dirty things your feet touched outside, so you should leave your shoes outside of your main entrance door, or just inside after the door. In my home, I expect that you remove your shoes just when you arrive, and just before washing your hands!

  • I listen to a lot of music, all the time, when alone at home. Except if a neighbor actively complains (they all have my phone number or can come knock, I have a paper on my door saying that I’m open to discussion anytime), I won’t force myself to stop my music or even reduce the sound volume at any hour. None of my neighbors in Rennes ever complained about that, and I actively asked about it to my closest neighbors, nobody complained so I guess I’m fine ;

  • I use a compost at home for anything that can go to a compost, and I expect you to use it (I can take care of it if you aren’t used to), in particular don’t throw away old vegetables and compostable garbage in the « normal bin » ;

  • I almost don’t buy anything that have wrappings, especially no plastic wrapping, and almost everything I eat is organic and based on vegetables, so I don’t produce much waste, and therefore I empty my bins quite rarely. You too can succeed this!

  • I ventilate my sleeping room in the morning and before going to be, and my living room twice a day as well. I had the habit of doing so way before the coronavirus crisis, but it is even more logical to do so nowadays.

Other people houses:

  • Of course, I am also aware that most people also apply domus mea praecepta mea rule to their own home, and that their rules most certainly differ from mine. I always try my best in being polite, and asking (as well as observing) as much as possible when I’m visiting someone for the first time(s). Don’t be surprised if I ask a lot of details these first times, like « can I remove my shoes? », « can I wash my hands please? », « do you want me to do something differently? please do ask, I’ll try my best in respecting your rules », etc ;

  • The same applies to shops, which are owned by people, and other public places, with the notable differences that any public places (including shops) must first respect the law ;

Concerning water at home

  • If you are lucky to live in an area where clean drinkable water is available at home, acknowledge that this is a privilege that about 2 out 3 of humans don’t have yet. You have to realize this privilege, and honour it. See below about « Concerning water outside home » ;

  • You have the right to like drinking other beverages than water, including beers and wines, cokes and soda, sparkling water etc. But be aware of their ecological and economical costs, as well as their potential impact on your health. Most certainly, regular water is better for you, in all aspects:
    • See below about alcohol, which are nice to enjoy from time to time but should never be abused, and whose consumption should be as limited as possible.

    • For fruit juices, if they are purchased in glass bottle, and from locally grown fruits, they can be bought from time to time (I usually buy a liter of apple juice, grown and produced 25 km south of Rennes, at Novoitou, every month or so, for ~4€/L).

    • For other beverages, I am highly against their existence, and have banned all of them from my life. I was never a big fan of soda and sparkling water and other useless but sugary and tasty alternatives to water. But the more I learned about their bad ecological footprint, their responsibility in the current obesity pandemic, and other facts, the less I wanted to drink any of them.

  • If you drink coffees, teas and infusions, you can make cold coffee or ice tea yourself, it is so simple: prepare hot beverage, put it in fridge, wait, then it’s done, it’s the cold beverage ready to be enjoyed!

  • Of course, please also keep in mind than drinking these beverages, hot or cold, have a higher ecological and economical cost and impact than plain water!

  • Try to ask yourself this question: right now, if you were to stay closed at home with nobody bringing you anything from outside, and if your incoming tap water was closed, how long can you survive? For most people, who don’t store any water at home, the answer is simply « a few days », and it’s scary and quite shameful! I am not pushing this to the extreme of having water tanks, or buying source water in large plastic bottles pack, but simply by keeping glass bottle and progressively and slowly keeping them filled with drinkable water, I usually always have about ~50L of drinkable water at home. This can allow me to live correctly for a few weeks, and to survive for up-to two months if I was stranded inside my home. This is of course more a though experiment than anything else, but still it is comforting to have enough water at home for a few weeks ;


  • I disagree with modern view that clothes should be cleaned every so often, but I do it almost as regularly as the average, for most of the clothes ;

  • I have never sorted my clothes between whites and colors, between delicates or not delicates, and I won’t do so ;

  • I don’t own an iron, and I will never do. I find it useless to iron clothes, and as a matter of principle I will never buy any clothing that would « require » ironing, such as a suit or « professional white collar shirts ». Additionally to the ecological cost, I just don’t want to waste my time ironing clothes ;

  • I am lucky to be able to not own my personal washing machine but use the one provided in my tiny building by my nice « landlord », this helps reducing my personal carbon footprint as this washing machine is shared with the other neighbors. We are 7 in total, and in almost 5 years living here, I can’t remember any moment when I was annoyed by having this shared washing machine. If it’s used when you want to use it, you simply come back two hours later. It’s always clean, and it’s free to use ;

  • I no longer buy laundry powder, I buy liquid laundry, using the same 3L plastic bottle since a few years, at a local raw store (« Day by Day » in Rennes). It is organic, locally produced in France, it smells amazing, and it’s cheaper in the long run than liquid or powder laundry of similar quality in supermarkets ;

  • You can even buy the raw cleaning products and prepare your own laundry. I will try this if I have to move and cannot find a satisfying solution that allow me to buy laundry with no wrapping and no one-time plastic bottle.

Fridge and freezers

  • I try to disable my (tiny) fridge as often as possible. Often, I have nothing in my fridge, sometimes just butter or some cheese, never any form of meat (read above for « Alimentation and food »), sometimes some rest of previous meals. Most of the things that pass by my fridge can survive a long time even if I disable it (except butter), so most of the times, my fridge is just disabled ;

  • Next winter, I plan to ban butter from my alimentation, just so that I can completely disable my fridge! If your kitchen temperate is low enough, except in summer, you can keep most cheeses (for up-to two weeks) with no need for a fridge!

  • However, in summer, I do have to admit that I really like having fresh water instead of room temperature water…

  • I do not have any freezer and I am aware of how much electricity they can consume ;

  • I never buy any frozen product, including ice-cream that I banned from my alimentation since 2020, as they simply have a too high carbon and energy footprint. Before banning ice-cream last year, I estimate my annual consumption to be less than 5 kg (meaning less than 10 times a plastic box), and I never bought any other frozen products.

Personal hygiene

  • Like for liquid laundry, the most economical and eco-friendly solution for your body soap, hand soap and shampoo is to buy them in solid form from a local, ecological soap makers (I like the brand « Savon l’Aubergine » in Rennes). The second best solution is to buy them in liquid form, using your own bottles, from organic and ecological grocery shops (like « Day by Day » in France) ;

  • You can also buy liquid soap to clean your dishes, using your own bottles, it will be cheaper and more eco-friendly than buying a new plastic bottle each time you run out of soap !

  • Shower every day, but don’t take baths or at least very not regularly ;

  • I don’t use shampoo for every shower, I read a lot about how too frequent shampoo can damage your hair. I tend to wash my hair once a week, and every time after sport ;

  • You have the rights to take long, hot showers, their ecological and economical footprint is negligible if you follow most of the advices and rules described here ;

  • If we compare the impact of green golf terrains to the impact of taking a 50% longer shower, the golf terrains clearly consume much more water. So in rich country, making people feel guilty about taking long showers, while allowing immense golf terrains, is pure hypocrisy. Of course, don’t spoil water, and don’t take 30min showers everyday, but if you are reasonable in every other aspect of your life (don’t own a car so don’t need to wash it, don’t own a swimming pool or a garden so no need for large quantities of waters, don’t buy meat or water-intensive vegetables such a corn, etc), you should not be ashamed about enjoying long showers ;

  • I guess you understood from the two previous points, I love to take long showers (long meaning a few more minutes than the strict minimum, never more than 12 minutes I think), and I was tired of people thinking that this « selfish » behaviors has a large impact. What is selfish is to play golf, take planes for a few days of holidays, to smoke, etc.

  • Brush your teeth at least twice a day. It’s honestly hard to think about doing so at lunch where you are at work or traveling, or even at home, but it’s easy to do it in the morning before leaving your home or after breakfast, and on the evening before going to bed ;

  • You have no reason to continue to buy disposable plastic toothbrush. You can buy at organic grocery stores or « zero waste stores » very good toothbrush that are more eco-friendly, and more economical! At « Day by Day » I bought in 2018 a plastic toothbrush with removable head, for about 8€, and each head last for 5 to 8 weeks, and cost 1.4€. It reduces the amount of plastic I have to buy, and it’s also easier to transport such toothbrush: I can wrap the detachable head in a tiny plastic bag or tissue, while keeping the long toothbrush in my work bag (for instance) ;

  • Buying plastic cotton swabs is illegal in France since 2020, and it was shameful before. Cotton swabs are proved to be bad for our ears! For a few euros, you can buy an ever-lasting metal or a long-duration bamboo ear swab, and you will never need cotton swabs ever in your life! I bought my metal one for about 6€ in 2018, and use this tiny metal ear swab on a regular (but not daily, it’s bad for your health) basis since then ;

  • The same idea goes for many items in your shower, in your bathroom and in your kitchen. I no longer use sponges for instance, for doing the dishes, but a plastic brush that I bought in 2016. That’s right, I have not purchased a sponge in the last 5 years. I have used 3 or 4 I think (that I had from before), to clean stuff occasionally, but on a daily basis, this small plastic brush is enough.


For all of these suggestions, think about the money saved, but most importantly, and the quantity of plastic that could be reduced if everyone did the same!

Concerning toilets

  • If you are lucky to live in an area where you can have access to proper toilets (at home or not), acknowledge that this is a privilege that about 1 out 3 of humans don’t have yet. You have to realize this privilege, and honour it. It is the result of more than 2500 years of history of technological and social evolution and improvements ;

  • As Tylen Durden says in the movie « Fight Club », soap is the indicator of civilization, but I would complete this statement that books and science, soap and showers, drinkable water and toilets are the three key indicators of civilization ;

  • If you are at home, you can safely try to reduce the number of times and frequency to which you flush your toilets, especially after just peeing ;

  • As a fun self-quantified experiment in 2021 (see self-quantified.en.html), I am counting the number of times I use my toilet and shower. It’s a simple yet fun thing to do. I use a tiny metal padlock for each, with 3 or 4 numbers from 0 to 9 (allowing to count up-to 999 or 9999), and I don’t (yet) write back the numbers regularly in a file or a notebook, even though I thought about doing so ;

  • If you live in a house with a big garden, you could consider turning to dry toilets, as there are much more eco-friendly. I tried this in a Woofing experience in a farm north of Rennes in October 2020, and it’s quite surprising how convenient the system can be if it is well constructed (no smell) ;

  • I don’t have much to write about toilets!

My views on slavery of animals

Yes you read it right, I did not save « ownership of animals » but « slavery of animals ». That’s my point-of-view.

Concerning dogs and cats

  • TL;DR: I don’t acknowledge and find outrageous the moral and legal ability of our societies to « purchase » and « own » another animals, including dogs and cats ;

  • I am not opposed to owning every form of living beings, just animals. By using the words « living being », I am aware that it is almost impossible to define what this means, and what « life » means. Here, I consider living beings as all species of plants, animals, bacteria and viruses and microbes, fungi, mushrooms and other hybrids species. We cannot live without bacteria (are you aware that in your gusts live up-to 2 kg of bacteria? they are essential to your survival as they help us digest and process food!), and while some viruses and microbes are the most deadly and serious threat to human life (looking at you COVID-19!), we also could not live without them. We also cannot live without plants and mushrooms, including vegetables, fruits, cereals and other plants that human societies have used and grown since the last thousands of years, but we can live without enslaving and exploiting animals ;

  • I’m very much aware that it is of course a very strong position, and most people are against it ;

  • The only exceptions are guiding dog for blind or disabled people, and (to some extent) service dogs for fire-fighters, rescue services and (to a lesser extent) police forces and especially drug enforcement at airport, etc ;

  • Of course, owning an animal is far less morally wrong than owning a human being, and human slavery and abuse of workers are serious problems that we (as a modern, enlightened society) should always fight against ;

  • From some data I heard and read, the explosion in the number of domestic cats in Europe and North America since the last century is responsible for the extinction of many local bird species. When your cat brings you back a dead bird or mouse, it’s not cute and fun, it’s just the tip of the iceberg: domestic cats and more generally domestic pets have a serious ecological impact, due to their very large numbers (in France alone, there are about 10 millions cats for 68 millions people, data) and their need for alimentation, medicine and specific purchases ;

  • My point of view is that every euro spent for a pet should rather be spent to help reduce inequalities and fight poverty in human populations, and that every kilogram of food that is being produced for a pet should rather be produced and given to people in need, in poor countries or even in your neighborhood (even « rich » countries have a non negligible share of their population suffering from ). Owning pets that are not useful for your survival (like a chicken which produce eggs and eat organic waste) is a privilege of rich people, and even just the concept of « owning a pet » (even without buying it) is something I tend to consider as shameful. How can we people find normal to feed their cats and dogs (that we bought and enslaved) with rich and good quality food, when homeless people live in the streets and have difficulty feeding themselves?

  • If you are concerned about your alimentation, especially about its ecological impact (and you should, see above), you should be as much concerned about your pets” alimentation! Being vegetarian, or at least aiming at reducing your meat consumption, appears to me as one of the most important decision someone can make to reduce their ecological footprint, but if you’re trying to become vegetarian (which will help the planet by reducing the carbon footprint of your alimentation, and reducing the morally wrong slavery of animals being slaughtered to feed you) while you have a dog which continues to eat meat, you should realize the flow in your decision making process ;

  • A close friend of mine, who helped me realize many things about the impact of producing and consuming meats and other product based on enslaving and killing animals (thanks L. in 2018!), always dreamt about owning a dog when she would be able to do so. She was also a strong believer of the importance of being vegetarian, and she agreed to let go of her dream, as owning a dog would most certainly require to buy dog food containing meat. I don’t think many people are smart enough to take such decisions, but you can do it!

  • If you have an animal at home and I come to visit, I expect them to not try to touch me, especially dogs. You are responsible for their behavior, and if you can’t prevent them from touching (or attacking) me, you should not « own » these pets. I will most certainly leave right away if your dogs (or other animal) appear as a threat to my safety, or just bark or jump at me. If I stay, you are of course responsible for the behavior of « your » animal, exactly like if we were outside (it’s the law). I can tolerate cats (even though I don’t like them and am allergic), but it is almost impossible for me to tolerate dogs, and I’m not sorry.

  • The more a dog breed is close to the wolves and old dog breeds, the less absurd I find that you would like to « own » such dog. They remind us of a time where our survival was dependent of these domestic wolves. I find ugly and useless almost all dog breeds, but find majestic and pretty breeds as sled or husky dogs. Other breeds, such as pugs, are abominations that humans should be ashamed of having created, they are not suited for existence and people should be ashamed of « owning » such living beings ;

  • Of course, I am highly against fishing and hunting, for « sport » or « fun », so if you own dogs because you are using them for hunting, I will probably consider you as a caveman, who is not yet aware of the invention of agriculture and the benefits of eating vegetables and fruits and other organic vegetarian products. TODO: write more against hunting and fishing?

  • Summary: I dream of a society who could act against slavery and « ownership » of animals, and remove this morally questionable right from its citizens. It wouldn’t need to be an abrupt decision (as it would require to kill millions of pets), but it could very easily be a long-term decision. The first decision should be to stop to « sell » animals, and slowly close all centers that industrially breed pets. The next decision can be to stop people from being able to adopt new animals, and slowly enforce existing animals to be castrated. In 30 years, without killing any living pets, we could remove pets from our society (except service and guide dogs, see above), and stop spending so much money and time and food on them. By doing so, we would reduce the moral impact of « owning » pets ;

  • Controversy: my point of view is extreme, and of course I understand that many people love their pets, have wonderful memories with them, and I do not want to steal these from anyone. But pretty much like almost nobody owns a horse nowadays while it was the most common animal in farms and cities, a century ago, I dream of a future where owning a pet for your pleasure (not for guide and service dogs, again) would be illegal, but most importantly, globally recognized as morally wrong, and would be fought actively. This is not an utopia or a weird point of view, it is simply the most logical continuation of the fight against human slavery. It is almost globally recognized all other the world that human slavery is morally wrong, and fighting against this old practice is very important (looking at you, Libya). If you live in a rich country and you own a human slave, you can face lifetime jail, and literally nobody can find this acceptable, no matter your reasons to « own » this slave. A few centuries ago, it was socially accepted in many modern societies that (mostly white) rich people had the rights to own (mostly blacks) slaves.

  • Conclusion: I dream of a future where no human would never again be enslaved, of course, but also where people would also realize that owning an animal is also very much morally wrong. Pet ownership cannot be compared to human slavery on the same level, of course, but both are wrong. Thus, I also dream of a future where virtually no pets or domestic animal would be found in our homes (except if you’re blind and need a guide dog), and no animals would be found in our farms. The first fight is course to remove animals in farms where they are enslaved in order to be later slaughtered for their meat, but later it will be to remove animals which are enslaved for their wool, eggs, mils etc. The next fight will be to remove pets and « useless » animals.

Voir aussi

One of my favorite novel ever is « The Cats of Ulthar », by Howard P. Lovecraft, a very short novel about an elderly couple who are not nice to cats. I loved this text ever since I was 11, and nowadays I could read it again by replacing very action verb that is aggressive against cats with just the simple fact of « owning » a cat. Spoiler alert: it does not end well for the elderly couple! You can read this novel for free, it is in the public domain, here on WikiSource.

Concerning cows that produce milk

  • Like for other ideas, I have mixed feelings and have not yet been able to converge on a rationally reasonable position about this aspect. I know that cows living in milk farms do not have the worst life condition, but they often are raped by mechanical machines to inseminate them artificially (see above about food), yet I think that for now on, the world is not ready to stop producing milk and dairy product. The first fight should be to stop slavery of animals being slaughtered to produce meat, and then later on we could hope to « turn vegan » everyone, by stopping slavery of animals being exploited for their milk ;

  • As of 2021, despite my strong beliefs against animal slavery, I have not yet turned entirely vegan. I have no consumption of the dead flesh of any animal (meat or fish), a very low consumption of animal-based product (mainly butter and locally produced cheese). I will most certainly continue to slowly decrease my consumption of cheese, and hopefully will soon stop entirely.

Concerning domestic service animals (horses etc)

  • Like for other ideas, I have mixed feelings and have not yet been able to converge on a rationally reasonable position about this aspect. Indeed, some animals have been historically used (and slowly bred) as « service » pets, like horses, donkeys, buffaloes and other mammals. Their genetic and biological history in the last few thousand years have evolved from our usages of these species. Basically all modern species did not exist a few hundreds thousands (100_000) years ago, and have rapidly changed in the last few thousands of years (like for vegetables, fruits and cereals!). Using these animals, especially horses, was a key factor in the rapid development of our societies, for travels, agriculture and industry. It was probably necessary, but it no longer is. But here comes the difficult decision: On the one hand, I guess I would like to see no animals being owned and enslaved by humans (especially horses), but on the other hand, I dream of a future with no personal cars and motorized vehicles, and a future with no motors based on gas. Reintroducing and using horses again as a major source of transport, using their muscular power instead of gas power, like before the 1900s, could be a good solution to help removing cars from our cities and rural areas ;

  • Similarly, using venomous snakes in a research lab in order to find antidotes and learn more about toxins, if it can result in « saving » human life, is a questionable practice: it can improve our quality of life, but it does require to enslave and possibly torture animals. The same goes for lab mice, and other « guinea pig » (cobaye) animals. My point of view would be: yes indeed we should aim at not using any animals for these tasks, but the first fight should be to remove animals from our world-wide alimentation, then pets from home, then animals having « real useful purposes » in labs.

Concerning domestic cocks and chickens

  • The fact that our ancestors have bred wild birds into becoming what is the modern day (man-made) species of domestic chickens is morally-questionable, but it was motivated by a question of survival. It no longer is, with modern vegetable fruit and cereals agriculture. We no longer need to have chickens and hens and ducks and other « domestic » birds in order to survive, thus this slavery must end, or at least, be drastically reduced ;

  • On the one hand, in our modern western societies, the vast majority of chickens (and ducks and other birds used for their meat or eggs) are found in industrial farms and live in cages or worst conditions. Stopping these farms from existing is a moral and economical and ecological priority for our societies ;

  • On the other hand, if you are living in a house with a garden, and you have enough space to build a small area that can host a few chickens and maybe a cock, and you can ensure their safety, their well-being (especially the fact that they won’t get hurt, that they will have enough food etc), then I guess it is acceptable to « own » a few of these domestic birds. In such house and garden, a few chickens can live pretty happily, and can help you reduce your carbon footprint by eating some organic waste ;

  • It is possible that if you have a large enough garden and land, owning a few porks, goats or sheep, can also have a positive ecological footprints, but I’m not yet sure (do you have data on this? please reach me out!). I saw a few small villages and green campus could using goats or sheep in order to eat grass and thus reducing the consumption of gas and human work for grooming grass. It is most probably a good think, all aspects considered ;

  • Summary: I dream of a close future where our societies would have completely banned animals from being enslaved and used for food production, hence where virtually everybody would be entirely vegetarian, where domestic pets such as dogs and cats could no longer be owned in small apartment and for no real pragmatic reasons, but where lots of houses could have a few chickens to locally produce eggs and help eating organic waste.

Concerning other pets

  • I am even more strongly opposed to the existence of any other pets, including birds (parrots and others), mammals (like mice, rats and others), reptiles (like turtles and snakes), insects and other tiny animals (including spiders) ;

  • The only always valid exceptions are for service and guide dogs, and to some extent, cocks and chickens and other « service » animals (see above) ;

  • The simple rule to keep in mind is: if you have animals before you claim you like/love them, just let them live in their natural locations!

  • In my opinion, no animal can hope to live a happier and healthier life while being imprisoned and slaved as your pet. This might be wrong about cats and dogs that their human « owners » (pretend to) love and take good care of. But my moral point of view is the following: if your pet is indeed happier at your home, maybe it’s because for the last 10000 years, our ancestors have enslaved and slowly changed this particular breed in order to make it dependant of living with humans, and while this was a question of survival for our old ancestors in Pre-Historic times, it no longer is, and thus this is no longer morally acceptable.

Concerning zoos

  • Zoos that keep large mammals and animals kept in small cages or small areas are morally wrong too, and I dream of a future where zoos will not exist anymore, but where humans would have succeeded in preserving most of the living species, possibly by building many more natural parks and protected areas ;

Concerning hunting and fishing

  • If you read anything from the above sections about alimentation, and pets, you might have guess my point-of-view against these ancestral practices of hunting and fishing wild animals. I am actively against these practice, and I find them morally wrong ;

  • I find outrageous the fact that during lock-downs in France, hunting had special privileges while simply walking in your street was limited: my mental health requires the right to just walk for a few minutes in my streets, and so does most people, but the fact that this fundamental right was limited while the right to go in the forest and kill wild animals was not is shameful and outrageous ;

Exterior life and safety rules

  • Never leave your apartment/house without checking that you have your keys.


I take this rule one step further: I always have my key attached to my belt and pants, and I have almost never walked from my room to my living room (where I can exit my apart) without said belt and pants. I got locked out of my student rooms a few times while studying at ENS Cachan, it was never a real problem as employees of the student housing service were always available nearby… but I also got locked out of my apartment in Rennes in 2020 in one evening, and it was not a nice experience, to say the least (I had to climb a wall of 3.5m from my neighbor’s garden - with their approval and help of course).

  • Never leave your home without at least 50€, or enough money to sleep in a hotel, buy a train or bus ticket to go see a friend, buy a disposable phone or similar things.

  • Tips: you can buy for less than 20€ a utility belt that has an interior pocket when you ca n store some money, and more tiny things (like a small invisible wire, a spare key to your home, a tiny µ-SD card with backup of your important documents such as passport etc etc). This can save you from uncomfortable situations!

  • If I’m outside and possibly interacting with people (in a street, a city bus, a shop), I find it uncivilized to wear earplugs and listen to music, and I never do it ;

  • If going out for more than 15 minutes, you should have a bag, with a few things on it:
    • your wallet or at least a piece of identification (passport, ID card, driver’s license etc) ;

    • drinking water ! In a glass or metal bottle, not a shitty plastic one ;

    • at least a book or something to read ot spend your time on (if you have to wait a couple of hours, and don’t want to waste them) ;

    • one or more other bags (such as foldable plastic or tote bag), in case you buy or find more things ;

    • a couple of clean masks, and hand alcoholic solution ;

    • a fork and/or spoon, especially if you plan on eating anything. Disposable plastic cutlery is one of the many things we should completely ban and our society should be ashamed of having this habit. Seriously, just pack a fork or at least a spoon in your bag or jacket, so you have one all the time with you! I do this since 2013, and most of the time I think about using it if I buy a meal to go!

    • Other things I always have on my bags include: a solid plastic glass to drink from, to order coffee or tea to go without using a disposable plastic cup, a Swiss knife, a few pills of basic medicine like anti-allergic anti-pain etc, tissues, one plastic bag, a detailed map of my city and especially with bus lines, pencils and a tiny notebook, a couple of stamps, if I know I’m buying cheese or other food that can be served in my own box or a meal to go, I bring my own glass box (Tupperware) ;

Some rules I try to follow because I live alone

I have lived alone almost always since 2009, and I am very happy about that. On the one hand it gives my all the freedom I need, on the other hand, it has some drawbacks and especially for my own safety.

  • When I’m traveling outside of my city, a few friends and/or family have details on my transportation (e.g. timing and number of the trains). They also know where I’ll be sleeping, with the exact address and phone number of the friend or hotel or stranger (using CouchSurfing) where I’ll stay. Most of the times, it’s quite easy: if I visit friend H. in Marseille, who is a close friend of my own friend A., I just have to say to A. « I’ll stay at H. until Monday, it’s so cool but we’ll miss you! » ;

  • More generally, at least two friends will know if I’m going to sleep outside of my own home, even if it is in my own city. They will know the name and phone number of the friend or partner where I’ll sleep, and I’ll be careful to text them again the next day so they don’t get worried about me ;

  • I could try to apply this rule more generally, as soon as I’m going for lunch or dinner somewhere outside my home and offices, but I haven’t started yet ;

  • If I buy something unusual, if I meet a new stranger, if I host a stranger or even a friend, I apply the same safety precautions and at least two friends will know. Most of the times, you don’t have to write anything scary like : « hey C., I’m afraid to host this guy from CouchSurfing so here are his details, just in case he attacks me … », but more something natural like « hey S., I thought you buddy because last time I hosted someone it was you, and tonight I’m hosting this girl from CouchSurfing, she’s from Berlin and named Alice, here is her number if you ever need to reach her while in Berlin! She seems so nice! ».

  • Lots of information about my professional work is available on my website(s) and professional social media accounts (i.e., GitHub and others), because I think it can only help me and help my colleagues if I happen to be unavailable for a lecture, ill or absent for a week, etc. It is also good for students, as they can find all the documents for a course, as well as more things if they are curious ;

  • I also like the idea of having a strong, long lasting, and easy-to-find presence online, so people can easily learn more about you, by just searching your name. Another advantage is that it can be useful to prove your identity if you have no identification paper on you. You can just ask someone to open their smartphone, their web-browser, go on your webpage, and they can then ask you details about you to check that you are who you claim. This can get easier if you chose to have photos of yourself available publicly (e.g., on your webpage). A simple trick is to host a picture of yourself on your website, hidden and protected behind a password, and that’s a way to have the best of both worlds (privacy of not having your face publicly available while being able to show a picture of yourself from your website if needed) ;

  • My parents or close friends have lots of details about my apartment, such as the digicode to enter, the phone number and details about my landlord, my main colleagues, my office(s), etc ;

  • The same goes for my computer and cellphones, and main online accounts, I feel safer if they know how to use them if i’m unconscious or unable to do it myself.

I’m not an expert on these questions, but most probably if you live alone (or even if you live with a partner, roommates or other people), these ideas and rules can most surely apply to your personal situation and could prove to be useful.

Walking in the city

  • In a street, I tend to walk on the left side, opposite of the cars in order to see them arriving in front of me and not in my back ;

  • As I wrote below about cars, I consider cars and motorized vehicles to be our greatest enemies, in modern Western society. I’m almost never afraid of people, even when walking alone at night, but I’m often scared and afraid of cars on a daily basis. They drive too fast, not precautiously enough, and as a citizen living and working in a city with no dangerous hobbies (e.g., I don’t hunt), the highest threat to my personal safety is a car accident ;

  • Never insult anyone, and always consider an insult as a great offense: it’s reprehensible by the law, and quite a serious offense ;

  • Never hit or reply to any oral threat, and only reply to defend yourself it you encounter any physical threat ;

  • For tiny things, it might feel like it is okay to lie, if it is helps you avoid an uncomfortable situation, but don’t lie except if you have to ;

  • Always put your own safety first, but in any case if you are witness to a violent situation, you have to intervene. It can be as simple as calling the police, taking pictures or recording a video or just the sound, or you can directly intervene, first to try to calm the different belligerents or to protect people being attacked from other people. If you’re alone against more than one dangerous-looking person, you probably shouldn’t try crazy things (don’t be a dead hero), but these situations are extremely rare in civilized societies (i.e., not the USNA with their crazy guns). It is however most likely that you can stand up for the victims and help them, by simply stating that you are against the violence of unfair situation you are witnessing ;

  • If you have to walk around with a valuable item such as a laptop, don’t carry it on an obvious laptop bag, but rather in your backpack, it will be less an obvious target for thieves ;

  • Never carry anything that you don’t have the right to carry, such as drugs (see above) and weapons.

  • TODO: write something about differences between dragues, harcèlement de rue, et agressions sexuelles?

Concerning water outside your home

  • Don’t ever buy plastic bottles. I am proud to not being able to remember the last time I spent money on a plastic bottle. I know in India in 2014/2015 I « had » to buy plastic bottles sometimes (but not regularly, I drank tap water without ever being sick), but I’m quite certain that by 2013 I already was fighting this toxic habit, even though I wasn’t as prepared and used to carry around a glass bottle, as I am now ;

  • You should cary on your bag a glass or metal bottle, and refill this bottle from your home before leaving, at your school or office, at bars or restaurants when traveling (they don’t have the right to refuse serving you, but they might have a right yo refuse you entering inside, especially in the times of this coronavirus crisis), or public water fountains that should exist in civilized and rich-enough countries. Clean drinkable water for everyone is one of the greatest achievements of modern societies, we should be proud of it and defend it and use it as much as possible. Buying water, especially wrapped in a plastic bottle, is simply an insult to more than 2500 years of social and technological development for building and maintaining a rich infrastructure which allows to produce clean water and distribute it all over a city, virtually for free for all the citizens ;

  • Don’t ever buy other beverages, especially cokes or soda, in plastic bottles or tin cans. Drink water, see previous point ;

Walking in mountains

TL;DR: I love hiking in mountains, and I am a very careful hiker, always prepared in order to have the nicest and safest possible experience during my hikes.

  • Never ever ever litter or throw away things in the nature. It is of course true in any environments, but most importantly true in remote and isolated natural spaces! Anything that you will throw, except natural compostable things (like a piece of bread), can last in the wild for dozen or up-to thousands of years. In a public park or a city, of course you also shouldn’t litter, but most probably there are public services working here to clean-up after you, so the impact will be less ;

  • I always have more water in my bag than necessary, usually I plan one litter for two hours, or one litter for one hour when hiking up on the mountain or if its very sunny. I also always pack tiny pills to clean-up and disinfect water, and so should you! They don’t cost much, they last years, and they can be very efficient ;

  • If you hike with me, I except that you will have everything in your bags for your own comfort and survival. However, I tend to be extra caring for my less-experienced friends, and most likely I’ll have planed to pack extra food and water for you, if you accompany me to a hike ;

  • I always pack a map of the area where I’m going to hike, and so should you! Apps on your phone like Google Maps are fine for city and roads and most natural environments such as forests and parks, but in the mountains, you can very easily find yourself in a location where you have no wireless Internet, or no GPS… You can also easily lost your phone, run out of battery, etc. Even in 2021, you have to learn how to use a regular 2D map printed on paper, and especially if you hike in mountainous areas.

Other exterior activities

  • Swimming?

  • Mountain biking?

  • Rock climbing?

  • Sailing?


TL;DR: I fight to ban and drastically reduce planes and flights, cars and motorbikes. I dream of a world with a hundred times more public buses, a thousand times more personal bikes, and only local and short-distance holidays. I dream of a world of perfect public service like public buses and trains and no need for any personal motorized vehicles, except for fire-fighters and ambulances, for professional such as for agriculture and construction workers.

  • I never ever allow myself to sleep in any public space, especially not in public transport such as trains or buses. It is too easy for someone to steal from you (e.g., money or your ID from your wallet, your laptop etc). I know at least two colleagues who got their entire bag with computer stolen from a public transport (respectively a train in Switzerland and a bus in Paris) while being asleep. It’s a stupid reason to get stolen…

Plane and airlines

TL;DR: I am highly in favor of deleting personal flights for tourism, and drastically reducing the number and frequency of plane travels.

  • In my opinion, to reduce the colossal ecological impact of the flight industry, we should aim at drastically reducing the number of planes in the world, and their frequency of travel ;

  • The target should be to simply forbid long distance travel for holidays or tourism. If you want to move your life from India to Canada, or from Brazil to Norway, do it once, and then try to stay there as long as possible, and even if you’re rich, don’t come back too often. Ideally, in 5-10-20-50 years we should try to remove all this ;

  • The world was functional and people were happy before the recent advent of the flight industry, we should aim at coming back to the simpler times for this ;

  • Governments should simply and right away start taxing the flight fuel as much as the other fuels and the flight industry as much as the other industries, especially for local short-distance flights for which train alternative exists ;

  • Scientific conferences should stay online after the coronavirus crisis, with more frequent local region- or country-wide events, and large world-wide conferences such as NeurIPS or ICML with thousands of participants should simply be forbidden to take place with the old model of having up-to 13_000 people flying from all around the world just for a few days of conference ;

  • Flights for business men should also be reduced as drastically as possible ;

  • I guess I would like to think that people shouldn’t be allowed to travel so far away for not so much money, when such a long distance plane travel has such a drastic ecological foot-print ;

  • I am guilty of having traveled about 54 times in a plane, for short (Paris - Rennes, once, Amsterdam - Rennes twice), middle (Marseille - Corsica, Paris - Florence, Geneva - Cadix) or longer distances (Paris - New Delhi four times, Nice - New York once) ;

  • I am extremely lucky to have been able to travel that much when I was studying and in my first years of professional career as teacher and researcher (one year in India in 2014/15 and a few travels in close Europe in 2016-19 for my PhD). I recognize the positive effects on someone of traveling, discovering other countries and cultures, foreign cities and other places. I value traveling a lot, yet I think it is something which is valued too positively in our modern culture: we are impressed by someone who traveled a lot, while we should rather be impressed by a farmer’s dedication to his lands, a mother dedication to her family, etc, but people who traveled a lot (I want to write « who traveled too much », like I did) should rather be ashamed of their very large ecological impact ;

  • I know that individual always have ecological footprints much, much lower than large companies (if you compare my impact to McDonald’s or Coca Cola footprint), but adding up the individual behaviors can get to pretty large numbers, regardless of what you measure and how count it ;

  • In 2018, I started to learn about the carbon foot-print of the flight industry, and the ecological disaster that are planes and heavy-carbon plane fuels. I therefore pledged to never take a plane again, and sadly I was (almost) forced to fly four times in 2019 for my last travels during my PhD ;

  • From June 2019, I swore to never fly again, and I will be respecting this oath very strictly ;

  • Note that for many years after my year living in India (2014/15), I dreamed of working abroad again, or in French islands in the Caribbean sea (Guadeloupe, Martinique) or in Africa (La Réunion). I was aiming at becoming a professor in prep’schools in La Réunion, but from now on, I value my oath and ecological fights, much more than my former dreams, so I changed my mind.


  • I love train, they are the most ecological solution to travel far away (or even as close as 10 kilometers away). Train are clean, quiet, they don’t move that much and allow you to work or read or even sleep in them, and they do not broadcast music or advertisements ;

  • I would like the European and French governments to sponsor more all the local (« TER ») train lines rather than the most fancy TGV lines, and I am sadden to see that night train lines and less frequently traveled local lines are going extinct. It is nothing but a shame to see than less and less kilometers of train rail are kept every-year, when the tendency should be on the other direction ;

  • Long train (or bus) travels are probably the only situation where I can listen to music from a smartphone or watch a movie on a laptop in public. Yet, I won’t get offended if someone interrupts, for a good reason.

Public bus

  • I don’t really like public bus, I prefer train, but whenever I need to go somewhere I can’t or don’t have the time to go by bike or by foot, I take the public bus ;

  • Please always pay your bus ticket, validate your card etc. Seriously, these buses are public services, they are usually very trustworthy and reliable, and we need to have more and more buses lines. Please do your part and pay rightfully these buses!

  • In Rennes, I like how most of the drivers are nice and very skilled. I like to say hi and chat a little bit whenever I can, and thank them for their great service. On the other hand, I am sadden to see that some bus driven can very quickly get aggressive and insult or even physically threaten you (it happened to me twice in a few months in 2021) if you calmly and nicely ask them why they are not wearing a mask…

Personal cars

TL;DR I’m highly against personal cars and other motorized machines like motorbikes! I pledge to never buy a car, to never drive any vehicle except for emergency or moving out, and I dream of a near future when only public buses, ambulances and delivery trucks will live on our roads.

  • I hereby pledge that I will never buy a car, a truck or any other motorized machines that come directly from Hell, kill hundreds of thousands people every year (RIP Thomas in 2019, Rémi in 2021), and pollute our atmosphere, public space and sound environments ;

  • I never understood how someone can enjoy driving: you have to be constantly careful about every actions your body and your mind make, and the tiniest mistake can directly damage or destroy your car, cost you hundreds of euros of repair, and even a small mistake can kill you, your passenger or anyone in the street. Why would I ever want to do that again?

  • I do think you should learn how to drive, because in an emergency situation it can be useful to know how to drive someone to a hospital, or to move a car which. Learn how to drive, then maybe practice it once a year to not forget too quickly, but THAT’S IT ;

  • I think people should buy a car only if they really cannot live without it. If your work is 45 minutes away by bus and you buy a car to win 30 minutes a day, try to compute the time (and money!) you will lose at the end of year when taking into account how much time you have to spend cleaning your car, buying gas, etc. Most probably, you won’t win anything!

  • I have a very strict point of view of personal motorized vehicles: for me, they should disappear as soon as possible. Our modern society could and should adapt as fast as possible to exist without any personal cars or motorized machines. The only remaining motorized engines should be: a) public bus (by multiplying the number of lines by 50x and their frequency by 2-20x), b) public service like firefighter, ambulances, official mail delivery, c) long distance and large volume transportation of food and goods, d) for professionals like in agriculture and construction works, plumber and other workers. We should aim at simply deleting personal cars from our society, as well as useless Taxi, and simply increase like crazy the number, frequency and reliability of public buses lines, with several different size and categories ;

  • I don’t like and I don’t trust taxi. In Rennes, taxi are loud, they drive too fast, they use the bus line when they shouldn’t (I know the rules say they can, but does a taxi really should count as a public service, when it’s only used by one rich person at a time? it’s unfair). I think it would be very easy to just remove them: governments could give a bus driver license to any taxi or Uber driver, and they will know be civil servant with a fixed salary, working for the greater good rather than for their own benefit ;

  • I am even more against motorbikes and personal scooter. The noise they make in cities is just too much, and almost anybody who has a scooter should be able to do the same travel by bike or public buses (and if you are not, the dream goal should be to enforce the local city of government to add a new bus line, not to solve your own problem by buying a polluting killer motorbike) ;

  • As long as personal cars will exist, I will continue to consider them as only negative things in the world: a) the worst enemies to pedestrian in cities and any environments (and the biggest threat to one’s safety and life), b) the biggest source of noise and air pollution in cities and alongside roads, c) possibly useful when hitch-hiking ;

  • In fact, in my opinion, the development and authorization of manufacturing, selling and buying personal cars powered by gas and motors constitute one of the worst decision ever made by mankind, and one of the greatest failure of our modern society (dating back as old as in the 1920s). It was mainly promoted by the newly formed gas industry, for financial purposes, and even if it did bring more freedom to the individuals, the negative impact this whole industry had on the environment (mainly from an ecological point-of-view) is incredibly bad. Of course, I know that motorizing the agriculture industry allowed to increase the production, and motorizing firefighter and ambulances, and the delivery of food and goods all allowed to improve our life quality world-wide, but these are the only three kind of motorized vehicles I would to see in the street and in our world ;

  • Car only exist so that you can occasionally use the car of one of your friend or relative in holidays or for exceptional travels (like moving out), or hitch-hiking ;

  • I am not saying I will never drive again, most probably I will « have to » at some point, but I definitely don’t want to drive on a regular basic (even once a week is far too frequent for me), and I won’t ever buy gasoline or car fuel ;

  • I consider than personal cars should have the lowest priority on the streets and roads and in cities, especially they should never have priority over bikes (see below), or pedestrians. You already illogically have the right to pollute our ears and air and atmosphere, to risk to kill us any time you move your evil metal monsters, and to take an absurd amount of public space, that’s already far too many rights for a bunch of killing machines, don’t you think?

  • And for the last time, no, my extreme position against car is not because I’m a bad driver. I just really don’t like it (kinda like programming in Java, I don’t enjoy it, but I still know more than enough) ;

  • And it also has nothing personal to do with my father who worked as driving instructor for 23 years, and who taught me how to drive in 2009-2012 ;

  • For a long time, I had a dual and unsettled position regarding personal motorized vehicles such as camping car, on one hand I find them very cool and they are an amazing way to travel and enjoy your holidays (I grew up living 4 to 6 weeks in a camping car every year, between 3-yo and 17-yo), on the other hand they share all the negative aspects of personal cars such as noise and air pollution, dependance on gas, easiness of killing or hurting someone when you drive, etc. I long dreamed of buying and owing my own tiny camping car, but I dropped the dream, and will never follow it again. My decision is now to be highly against camping cars as well ;


TL;DR I’m highly in favor of a more global adoption of the bicycle as a major transportation engine.

  • Thanks to my awesome parents, I’ve owned bikes since I was a very young boy. As a young adult, I received my Orbea (black and white) mountain bike when I was 17 year old, and I still use it daily, 11 years after. I have used this bike on a daily basis for all my transportation since 2016, when I was living in Lausanne (Switzerland), and then since I moved in Rennes ;

  • I love biking, whether it is for fun or for sport, and also for fast, quiet and ecological transportation in urban areas or in the mountains ;

  • I’m against the boom of electrical bike. The only two reasons to buy such electrical bikes can be the following :

    • you don’t have the physical capacity to bike to your work/school without the electrical assistance (e.g. it’s hilly or too far away), and all your alternatives are more polluting (e.g., a car, a bus) ;

    • you don’t have the physical capacity of using your bike for sport and to have fun, and this electrical assistance can help you do more sport ;

  • I think people who owns a car should be advised or maybe even forced to also buy a bike, and we should globally promote a more frequent usage of our bikes, to short distances ;

  • It’s very convenient to go to a grocery store with your bike (or kick-scooter), you can put a lot of weights on your handlebars (by evening the weights, I can bring back much more weight than with my arms) ;

  • Biking is good for your health ;

  • You can hardly kill anyone using your bike, even if you drive fast and don’t pay much attention, while it is surprisingly easy to hurt or kill someone when driving a car or a motorbike ;

  • I dream of a society where bikes would be owned by virtually everybody, and will be so cheap that basically nobody would want to even steal your bike ;

  • I dream of cities with almost no parking spaces but large walking areas for pedestrians and large lines reserved for bikes.

For the safety of my bike:

  • I have an identification number engraved in my bicycle, using ByCycode, which was engraved by a benevolent member of Rennes bicycle association (Rayons d’Action), of which I am a (non-active) member ;

  • I take regular pictures of my bike, when I park it in unusual places, so that I have a picture I could show to the Police if my bike gets stolen ;

  • I have a locker and a very strong padlock, one using a number (it’s 1201 by the way - yes I feel safe saying it here), one using a key that I keep in my pocket and belt (the long and thin black one). When I park my bike I always attach both front and back rows, and my helmet and the frame ;

  • I added a padlock to my bike to protect my saddle, as it got stolen in 2018 and I was annoyed by this stupid uncivilized gesture. I bought a better quality 35€ saddle, and added a 10€ padlock, securing the saddle to the frame. Of course, even a cheap pliers could be enough to cut this padlock, but it’s already something I could do easily. My saddle was not stolen again ;

  • I have a tiny bicycle air pump attached to the frame, as it is very useful to quickly refill your tires before riding ;

  • I also have a water bottle attached to the frame (see above about water).

For my own safety and the safety of others:

  • I always wear a green reflective vest and a helmet, as well as reflective strips on my pants, and so should you! Not wearing a helmet on your bike is like driving with no seatbelt: okay it was weird at first, and it’s not so convenient, but I can and it will save your life ;

  • I always wear tiny lights on my bike (white in front and red in back), as well as very bright personal light on the torso. For ~50€ in Decathlon, you can buy these wearable lights that can be recharged using USB, and they can literally save your life from murdering cars that don’t know how to drive. If you bike at night or when the sun is not yet up, or in foggy or bad visibility environments such as tunnels, you HAVE to wear such lights ;

  • I got hit by cars a few times in 2016 and 2017, before I had all this protection, and once in 2017 I got hit quite severely by someone, when biking by night with no lights. I was guilty of not having any lights, but he or she was responsible for not seeing me, refusing my priority (I was already in the roundabout), and for leaving me lying (apparently dead) in the middle of said roundabout after hitting me. As I said above, cars and other motorized vehicles are your deadliest enemies ;

  • I am extremely careful against any large vehicle such as buses, trucks etc, as I am aware of their large blind spots and occasional rude driving habits. I am very much aware that any such vehicles, and even a car when it goes enough, can kill me in an instant if I’m not careful enough, or if they do any mistake or want to hurt me. I lost a close family member to a car accident while he was cycling in November 2019 ;

  • I check my front and back brakes before leaving on my bikes, as well as my tires, and I re-inflate my tires very regularly. I control my chain and brakes and most parts of my bikes myself regularly, and usually once a year (in the summer) I bring my bike to a professional for a quick check-up. It costs less than fixing it after an accident, and I like the idea of spending some of my money to support professionals mechanics who chose to work for bikes instead of the evil car industry!

  • On one hand, I do my best in respecting the driving rules when I bike in France, especially regarding red lights, roundabouts and priorities. I can get very annoyed if a car or another bike or anyone don’t follow these rules, especially if your stupid behavior is a danger to myself or others. I had and will continue to actively notify drivers of their bad habits, by talking or shouting or waving at them whenever it is required.

  • On the other hand, I tend to consider that bikes should have priority over cars, as they are more ecological and respectful of other people (don’t do noise, don’t take public space on the street, can’t kill you, don’t smell bad, etc). Whenever I’m not putting myself in danger and not violating any rules, I act as if bikes indeed had the highest priority over other vehicles (and I defend my right to do so) ;

  • I also think bikes should have priority over pedestrians as well. This last remark comes from the main mechanical argument that bikes have inertia, while pedestrians don’t, so it’s globally more energy-preserving to let bikes have priority, whenever it’s not a danger to pedestrians. Of course, whenever a pedestrian is already crossing the road (for instance), I’ll let her/him pass and I’ll stop, but I am thankful for people who are smart enough (or not in a hurry) to do the opposite, and whenever I walk I apply the opposite rule and consider bikes to have priority over me.


  • Hitch-hiking is the best way to travel while meeting new people, and taking your time and risking randomness ;

  • I am proud to have traveled for free for more than 6000 kilometers using hitch-hiking in France and close Europe (see hitch-hiking.en.html), and I am admire my friends or family members who have done even more (go Fabian!) ;

  • If you drive and you have the time and a free seat in your car, you should take hitch-hiker. Maybe be more careful if you are alone, or a woman, or if you are afraid of strangers. But I believe in a world where everyone should be nice, hence one should not be scared of strangers, so one should always open their car to hitch-hiker. Statistically, you are far more likely to be attacked, assaulted or even raped by your own family relative or friends, by your partner, or by someone following you in a street, than by a random hitch-hiker. I believe in this number, and most probably you should too ;

  • Basically, in my last 12 years of life, about 70% of the times I was in a car was because I did hitch-hiking with pure strangers, 29% because I was in a car with a family member or a friend, who would have traveled even without me, and 1% was in a location vehicle to move between two apartments or in a friend’s car I was driving for a personal reason ;


TL;DR: if you have to travel but there is no train available for this time or destination, if you have heavy luggage or a precise timing to respect, or if you are afraid of hitch-hiking, then using once in a while a car-pooling is acceptable, and should be preferred over using your own car or renting a car.

  • I like BlaBlaCar in France, but I really prefer hitch-hiking. In fact, BlaBlaCar was free at the beginning, and free alternatives still exist like but they are not so popular and not many people use them, unfortunately…

  • If you can avoid buying a car because a colleague or friend or neighbor can drive you to your workplace or school, that’s amazing!

  • If you can find a car-pooling solution for your holiday or occasional travel, and if there is no alternative using train (which pollute far less than cars!), then it is acceptable to do so ;

  • As for anything else, the most ecological and economical friendly gesture you can make is simply to not travel (like for food or clothing, the best action is to not buy unless necessary!)… so between two choices of taking a car-pooling to go somewhere just for fun, and not going and doing something locally, I will of course always choose to not travel.