Do We Know Anything For Sure?

Rene Descartes

There are many reasons we might want to philosophize—to become better people, gain self-knowledge, understand the history of thought, etc. But I was drawn to philosophy because I wanted to know, as far as is possible, what was true. This sentiment echoes the first sentence of the first book we read in my very first college philosophy class, way back in 1973. They are the opening lines of Descartes’ Meditations on First Philosophy:

It is now some years since I detected how many were the false beliefs that I had from my earliest youth admitted as true, and how doubtful was everything I had since constructed on this basis; and from that time I was convinced that I must once for all seriously undertake to rid myself of all the opinions which I had formerly accepted, and commence to build anew from the foundation, if I wanted to establish any firm and permanent structure in the sciences.

Later I read Descartes’ Discourse on Method where he states the origins of his doubts:

I was nourished by study from my earliest childhood; and since I was convinced that this was the means to acquire a clear and certain knowledge of all that is useful in life, I had an extreme desire to learn. But as soon as I had finished a course of studies which usually culminates in one being accepted as one of the learned, I changed my opinion completely; for I found myself troubled by so many doubts and errors that the only profit I had gained in seeking to educate myself was to discover more and more clearly the extent of my ignorance.

As many of my readers know, Descartes begins with skepticism but doesn’t end there. In fact, he’s trying to do the opposite—rid himself of his false beliefs so that he can replace them with true ones based on the firm foundation of clear and distinct ideas. He concludes that “I think, therefore I am” is that foundation. And this presumably indubitable proposition leads to the discovery of other clear and distinct ideas for Descartes—most notably the existence of the external world and God.

Then as a graduate student, I encountered  Edmund Husserl‘s Cartesian Meditations: An Introduction to Phenomenology.Edmund Husserl 1910s.jpg In it, Husserl developed what he called presuppositionless philosophy—the idea of philosophy without any presuppositions. He criticized Descartes for beginning with what he saw as unjustified presuppositions about the cogito. How did Descartes know there was an “I” doing the thinking? Instead, Husserl believed he could place philosophy on firm foundations by examining subjective consciousness.

Yet a problem bedevils those who seek foundations of knowledge. On what foundation does that foundation rest? And, if we ask this question indefinitely, we find ourselves in an infinite regress. Aristotle avoided this regress by appealing to intuitive truths, basic laws of logic on which all knowledge is based—the law of identity, the law of the excluded middles, the law of non-contradiction. Another approach is that of Jean Piaget who argued for “the circle of the sciences.” The idea that one science reduces to another in the following order: psychology -> biology -> chemistry -> physics -> mathematics -> logic and then back to psychology, thus forming a circle. (For a detailed discussion see my Piaget’s Conception of Evolution.)

A different approach rejects foundationalism altogether. Consider the following quote from the Austrian-born philosopher Otto Neurath,

“We are like sailors who on the open sea must reconstruct their ship but are never able to start afresh from the bottom. Where a beam is taken away a new one must at once be put there, and for this the rest of the ship is used as support. In this way, by using the old beams and driftwood, the ship can be shaped entirely anew, but only by gradual reconstruction.”1

In this vision of philosophizing we always necessarily begin in the middle. We can’t escape our situation or get outside of ourselves to construct some foundation. According to Neurath, contra to Descartes and Husserl,  we can’t raze all that came before and begin anew but philosophical inquiry can improve our pre-philosophical views.

I think this is about right. While I desperately wanted firm foundations for my philosophical beliefs when I was a teenager, I long ago gave up that dream. Even my intellectual hero Bertrand Russell came to a similar conclusion. In  Portraits from Memory and Other Essays, he wrote of his reaction to Gödel’s ‘Theorems of Undecidability’,

I wanted certainty in the kind of way in which people want religious faith. I thought that certainty is more likely to be found in mathematics than elsewhere. But I discovered that many mathematical demonstrations, which my teachers wanted me to accept, were full of fallacies … I was continually reminded of the fable about the elephant and the tortoise. Having constructed an elephant upon which the mathematical world could rest, I found the elephant tottering, and proceeded to construct a tortoise to keep the elephant from falling. But the tortoise was no more secure than the elephant, and after some twenty years of arduous toil, I came to the conclusion that there was nothing more that I could do in the way of making mathematical knowledge indubitable.

Life is full of ambiguity, and we either tolerate it, ignore it, or escape into a fanatical ideology. We can never be absolutely certain of anything; we know of no absolute foundation on which to build knowledge. In the end, I’m a fallibilist, any idea I have might be wrong.

Still, we needn’t accept epistemological relativism either because … some ideas are much more likely to be true than others.


  1. Otto Neurath (1921), “Spengler’s Description of the World,” as cited in Nancy Cartwright et al. Otto Neurath: Philosophy Between Science and Politics, Cambridge University Press, 28 Apr. 2008 p. 191
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11 thoughts on “Do We Know Anything For Sure?

  1. This is an area I don’t really know much about (pun intended). I guess this area is what it is called “epistemology “. I wish I could say I have read Husserl and the others, but I have not.

    But I remember some years ago, being alone with myself, and thinking: “I have to learn something here. I want to know the TRUTH.”.
    Of course, I haven’t found any “absolute truths”. I would be insane if I’d claim that. But the last sentence in your excellent article, works very well, I think.

    Also, I think the problem is that we want to find a “one size fits all” truth to this or that. But every life is different, every person, there’s so many variables. I think there’s absolute truth, i.e. if I hit my finger with the hammer, I get hurt. But other things are impossible to say if they are true or not, in every case. For example, I completely agree with Schopenhauer’s ideas of people in general: you are better off alone. Many other philosophers had similar ideas too, they can seem misanthropic, but this is not true (i.e. they didn’t dislike all people): every one of them would never dislike a good person. But in the main, we think people are best avoided: a lot of them are bad, some are neither good nor bad, and very few are good. We would never try to avoid the latter, but since it would be very difficult or impossible to meet only good people, we try to avoid them all.

    But these things apply to people like myself, Schopenhauer, Diogenes Of Sinope, etc… (I am not saying I am one of them, or that I am even remotely remarkable as they were) But what applies well to us, do not, and should not apply, to all. I would never tell to a child to avoid his classmates, simply because I think people are bad. To the contrary, I would encourage children to go play with other children, make friends, etc. I know that with this choice there would be even strong probabilities that some of them could end up having bad experiences, for example they could encounter some mean children. But such risks, I think, should be accepted. I would be mad to tell children to avoid people simply because some could be bad.

    So what is the truth? Are people bad or good? I think a lot of “truths” are contextual. I think the best thing is to be broad minded and to judge according to context. But also, many things are certainly true, and many are more true, or less so, than others.

    As Russell wrote: “Stupid people are cocksure; intelligent ones are full of doubts.”. I think that there is a lot more to be found in this statement: it is because one is not a fool, that feels doubt, precisely because he feels as if he were entering an immense world naked, so to speak. He knows that knowledge is incredibly vast and that there will be always things to learn and think about, that essentially it is a never ending process. Whereas the fool thinks : “Yeah, I get it.” without having learned anything (I think it is perfectly fine to have this thought if one has learned something, or enough. Whenever I read of Socrates having said: “Sorry, I don’t anything”, I am skeptical.).

    Of course, here I am not speaking about delusions, religion, etc.
    But overall, I don’t feel too bad for myself, considering all the fools we have around us, from the ones who think Covid is “a lie”, how the Earth is flat, etc.

    Come to think of it, one like you is millions of years ahead of most people. Some things are true enough. I think it is a bit like martial arts: there’s no single move that can win every fight or opponent. I think this could apply to things like chess too, but I don’t know anything about chess, so it is mere speculation. But I am probably not far wrong, although I cannot be sure 100 per cent.

    Sorry about my ramblings, lack of clarity, typos, etc….Thanks for your article!

    PS. actually, in regard to what I said about children avoiding other people, I am now not so sure I would encourage them to play with other children. For a moment I imagined the world like it was 40 years ago when I was a child, i.e. you get out of the house and play with other children. But now it is a very different story, with all the stupid social media craze. Obviously, that’s a terrible way to “meet people” even for adults, let alone children! But I digress.

  2. This is a timely entry for me. Two weeks ago I arrived in Vienna for a 7 week stay. I recently began reading David Edmonds’ book “The Murder of Professor Schlick” which is all about the Vienna Circle, which included Otto Neurath. I really like that paragraph of his that you’ve quoted. It fits my notion of evolutionary epistemology perfectly.

    Have you seen Andy Norman’s new book “Mental Immunity” yet? It also takes on these issues, which I reviewed extensively on my blog recently.

  3. no but I’ll check them out asap. thanks. And of course something of Schlick’s murder by a student. What a shame.

  4. I always enjoy and learn from your comments Luigi. Your example of covid was timely. In the USA we have the celebrities and athletes who couldn’t pass first-year biology or chemistry quite certain they understand subjects that scientists, who are much much smarter than they are, have spent a lifetime studying. And worse still these people have megaphones to spout their nonsense. What a world. I’ll listen to them after they have received their BS, MS, PhD, did post-doc studies, and spent years in the lab.

  5. Dear John,

    for every small thing you learn from me, I learn ten big ones from you. No, make it fifteen.

    The celebrities and athletes you mention are mostly pathetic people affected by the Dunning-Kruger effect: they think themselves a lot smarter than they really are. As every fool does. As you know, Socrates knew a thing or two about them. I always imagine him going barefoot in Athens, shaking his head in disbelief thinking of all the fools he found around. Something never changes. 🙂

    “In general, all the wisest people of every age have said the same things.
    Likewise, all the fools of every age have done just the same.
    And so it will continue.”. -Schopenhauer

    PS. I cannot agree about philosophers of every age having said “the same things”, of course, but I don’t think S meant this in a literal sense.

  6. In 2017 you wrote an article,
    ‘Is Trump An Asshole?’
    ‘Trump’ and ‘Asshole’ in the same sentence is redundant. Some things we do know for sure.

  7. Just reading now on BBC News about someone struggling with long Covid, here’s what she says:

    “Do your own research. There is plenty of information out there but please go to trusted sources of information – don’t trust everything you read on social media,”.

    Here’s an answer that I believe most of us would give: “No, fool. Do NOT do your own “research”, and do not trust ANYTHING you read on social media. In fact, (unless you are a fool), do not read ANY information on “social media”. Social media is NOT a source of information. NEVER read anything on the stupid social media. Social media is just there to say hello to some people you know, or if you are a dumb celebrity, to let your 15 year old “fans” know what you had for breakfast, or other useless and trivial such things. Social media is NOT Stanford University, or even Wikipedia. Get it? Probably not…”.

    I mean, it’s so darn simple. Duh. But, fools will be fools. Andy Norman’s book is certainly interesting, however from the few and (very) fast facts I gather about the book, the assumption about critical thinking skills is that “gullible people” who believe stupid things about Covid being a lie, etc, “are in fact too critical”. No, they are not, since using critical thinking skills doesn’t mean just being critical, but being logical and being capable of discerning facts from rubbish, which these feeble minded people are incapable of doing.

    And I believe the reason is….(drum roll) as the one explained by Schopenhauer: stupidity and intelligence is for the most part innate. “A fool who is born a fool, will die a fool.”, as S sweetly points out.

    This can be also observed about criminals: some of them just cannot stay out of jail, and as soon as they get out, they engage in the same crimes, or worse, than the ones they engaged in before. Here we have, say, two people, raised in the same negative environments, having similarly bad parents and influences, etc…. yet this person becomes a criminal, and the other does not (this can be proven with real life examples).

    However I have not read Norman’s book yet, so I don’t want to put the cart before the horses, so to speak.

    Apologies for the anger transpiring through these lines, but I cannot suffer stupid people. In fact, and this can seem mean, I hope they get ill with Covid and die, get long Covid, etc. I think the rest of us had enough of these stupid people. It is ok to be stupid, provided one doesn’t endanger others.

    Wasn’t this the reason why all the most eminent philosophers were against “democracy”? I.e. no one makes choice for the benefit of all, but just because they want to believe whatever stupid things they want to believe.

    (You are free to not publish this message at all, John. I would understand. Thanks, regardless. )

  8. John,

    have just read about someone who has been denied a heart transplant because he was unvaccinated (the hospital followed a policy about shortages of organs and priority given to people with the highest chance of survival). A relative said : “the Covid vaccine goes against his son’s “basic principles, he doesn’t believe in it”.

    Stupid world. 🙂

  9. After the comic relief will get back on-topic, though it is a broad topic—to say the least. Not being a philosopher, what strikes me is how we necessarily separate ourselves from the cosmos (subject-object dualism), when we are not.
    We are in the cosmos and the cosmos is in us.
    What comes immediately to mind is how the space between our atoms is relatable to the space between stars; the space between galaxies. Given that, how can we know truth?

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