- Thalès of Millet was so spaced out that he fell into a well while looking up at the sky. And died.
- According to other sources, the founder of skepticism, Pyrrho, had to be constantly rescued from the bottom of precipices or protected from rabid dogs. He also let loved ones die without rescue because he refused to believe in danger.
- In defense of the skeptics, Montaigne called philosophers who claim to know something crazy: "Human science, he says in Essais (II, §12), "can only be maintained by unreasonable, mad and forcible reason.”
- Hume sometimes regarded his philosophical speculations as a "melancholic delirium" from which only ordinary life (a game of backgammon, a good dinner, chatting with friends) could cure him (Treatise on Human Nature, 1.4.7-9).
- Thomas Reid and the common-sense philosophers regarded other philosophical doctrines as nonsense worthy of irrational Yahoos ("Such philosophy is justly ridiculous, even to those who cannot detect the fallacy of it. It can have no other tendency, than to shew the acuteness of the sophist, at the expense of disgracing reason and human nature, and making mankind Yahoos" (Reid 1764: 10)).
- Voltaire portrays Leibniz as a happy fool, and after mocking Rousseau's positions, advises him to "come and restore [his health] in the native air, enjoy freedom, drink with me the milk of our cows, and graze on our grasses" (Letter to Rousseau, August 30, 1755).
- Nietzsche, who liked to play doctor, saw a form of mental illness in philosophers' tendency to look for reality behind appearances (Gay Science).
- In The World as Will and Representation (II §19), Schopenhauer characterizes the solipsistic philosopher as a madman to be placed in a madhouse and refuted with cold showers (although few philosophers explicitly claim to be solipsists, many seem more or less committed to such a thesis).
- In one of philosophy's most famous gags, Wittgenstein mocks his colleagues with these words:
I am sitting with a philosopher in the garden; he says again and again 'I know that that's a tree', pointing to a tree that is near us. Someone else arrives and hears this, and I tell him: 'This fellow isn't insane. We are only doing philosophy (On certainty, §467).
- In an article on Derrida, Foucault, madness and the Cartesian dream argument, the historian of philosophy Ferdinand Alquié (1979/2023), a specialist in Descartes and teacher of a great number of French Theory figures, puts it even more bluntly: "No one would become a philosopher if he wasn't first a bit mad".
- The Irish philosopher John Oulton Wisdom (cousin of the homonymous “Cambridge realist") explained the "unconscious origin" of Berckeley's idealism by the Anglican bishop's pronounced disgust for his own excretions...
- More recently, some experiments have suggested that in many moral dilemmas, utilitarian philosophers, who believe that a good action maximizes collective well-being and legitimizes the sacrifice of a few for the community, act like psychopathic patients.
We could undoubtedly multiply the examples (if you have any to hand, I'd be happy to add to the list). But first, a question: why do philosophers so frequently call each other crazy?
As we've seen, they invoke a wide variety of reasons for considering their colleagues to be deranged, and these reasons are sometimes antagonistic (skepticism, dogmatism, etc.). This might suggest that their accusations are merely a stigmatizing, but unfortunately banal, way of marking one’s disagreement. Like politicians or car drivers, philosophers would say "crazy" to say "you, yuck", "you really, really wrong".
There is, however, a deeper reason. After all, many philosophical doctrines can actually seem crazy. Think of Leibniz's monads without doors or windows, the Eleatics who deny the possibility of motion, idealism according to which this table is made up of ideas, or even the recent illusionists who claim that consciousness doesn't exist. Imagine stopping someone in the street and convincingly asserting one of these theses...
Here, I'd like to try and explain this madness or appearance of madness –call that philosophical insanity— and determine whether we can (and should) find a remedy for it.
1. The crazyist hypothesis.
In a series of articles culminating in the recent publication of his book The Weirdeness of the World, Eric Schwitzgebel has proposed what looks like a defense and explanation of philosophical insanity. His main thesis, which for a time he called "crazyism", is that when it comes to the fundamental problems of philosophy, and metaphysics in particular, we are all committed to crazy or (he now prefers this term) weird doctrines, i.e. theses that are both bizarre (contrary to common sense) and dubious (poorly justified). To support his point, he multiplies examples of weird classical philosophies (the choice is embarrassing) and, more profoundly, shows that in a large number of fields, it can be proved that a disjunction of weird propositions is necessarily true. If you want to engage in one of these fields, you'll have to adhere to a weird proposition.
When it comes to the mind-body problem, for example, we have to choose between classical materialism, according to which everything is material (which, he argues, implies that the USA is a conscious entity), idealism, according to which everything is mental and matter does not exist (which is obviously bizarre), dualism (which he says involves oddities concerning mind-body interactions and the extension of conscious entities) or even more weird conceptions to the effect that we are not really conscious (eliminativism) or that even electrons are conscious (panpsychism). None of these theses is individually well justified, but we have to choose one.
Why should philosophers be condemned to defend weird theses? Fundamentally, according to Schwitzgebel, because common sense, understood as the sum total of our shared beliefs, is contradictory.
Common sense is incoherent in matters of metaphysics. Contradictions thus inevitably flow from commonsense metaphysical reflections, and no coherent metaphysical system can adhere to every aspect. Although common sense serves us well in practical maneuvers through the social and physical world, common sense has proven an unreliable guide in theoretical physics, probability theory, neuroscience, macroeconomics, evolutionary biology, astronomy, medicine, topology, chemical engineering.... If, as it seems to, metaphysics more closely resembles those endeavors than it resembles reaching practical judgments about picking berries and planning parties, we might reasonably doubt the dependability of common sense as a guide to metaphysics. Undependability doesn't imply incoherence, of course. But it seems a natural next step, and it would neatly explain the historical facts at hand.
As I understand it, Schwitzgebel's idea is that in order to develop a metaphysics that is not bizarre, one would have to rely on common sense, but that common sense contains certain theses that are implicitly contradictory, so that by relying on it, one is necessarily committed to a thesis that directly contradicts common sense. Such a thesis will, by definition, be bizarre, and insofar as it is directly contradicted by common sense[1], probably dubious as well. A similar explanation has been articulated more precisely in several publications by Bryan Frances, who sees the whole of philosophy as a field of paradoxes that definitively refute common sense (cf. e.g. Frances 2022).
Schwitzgebel's hypothesis provides a fairly plausible interpretation of philosophers' accusations of insanity. According to this "crazyist interpretation" (let's call it that), (1) a thesis contrary to common-sense beliefs would seem crazy (2) and common sense being contradictory, philosophers who rely on common sense would necessarily have to endorse doctrines contrary to common sense. Even though Schwitzgebel does (as I understand him) not recommend it, this crazyist interpretation naturally suggests a remedy for philosophical insanity: entirely give up common sense
Schwitzgebel's analysis raises a number of tricky questions.
- Why is common sense - understood, once again, as our shared set of beliefs - contradictory?
- Given that our common beliefs are subject to change, and that philosophers have supposedly been pointing out the problems posed by these common beliefs for over 2,500 years, why haven't we succeeded in reforming common sense to expunge its contradictions? For example, why haven't we, as some have long suggested, wiped the slate clean and replaced common sense with the scientific conception of the world?
There is an answer to these questions that suggests, it seems to me, an alternative interpretation of the accusations of madness hurled at philosophy, and a very different diagnosis, one that calls into question not common sense, but philosophy itself.
2. The Selenian hypothesis
Let's start with a few critical remarks on Schwitzgebel's assertions. Even if our common beliefs imply contradictions, it seems to me unfortunate to say that common sense is contradictory when it comes to metaphysics. Not because common sense wouldn't pronounce on metaphysical issues (I think it can indeed pronounce on them), but because common sense doesn't just consist of a set of shared beliefs. Properly understood, it also includes a way of thinking with these propositions, which can easily defuse contradictions. To show that the common-sense beliefs that A, B, C and D are contradictory, the philosopher must both consider all these propositions together and make a series of inferences from them. He will tell us, for example, that A and B imply E, that E and C imply F, and that F implies non D, which betrays a contradiction hidden in common sense. But this procedure, which requires us to step back and consider a large number of propositions at a glance, and to draw out complicated reasoning, seems far removed from common sense.
Anthropologists noticed early on that contradictions could be inferred from the beliefs shared by the peoples they studied, but that these contradictions, which did not arise in ordinary contexts, were of no interest to them:
Azande do not perceive the contradiction as we perceive it because they have no theoretical interest in the subject, and those situations in which they express their beliefs in witchcraft do not force the problem upon them. (Evans-Pritchard 1937)
It would be worthwhile to study this empirically, but from what I've seen in the bars of Paris and its greater suburbs (where revealing that you're a philosopher earns you the loquacious sympathies of many a fellow bar-goer), it seems that here too, common sense is uninterested in the contradictions that its beliefs might conceal. Why is this? Probably, like in the Azande case, because they can't appear in ordinary contexts, and the contexts of reflexive hindsight in which they are produced seem very different to people. We can illustrate this with what is undoubtedly the second funniest gag in the history of philosophy, again by Wittgenstein, who presents us with a situation where an outside observer attempts not to derive a contradiction from a tribe's beliefs, but the economic equivalent of a contradiction, i.e. an arbitrage opportunity.
People pile up logs and sell them, the piles are measured with a ruler, the measurements of length, breadth, and height multiplied together, and what comes out is the number of pence which have to be asked and given. They don't know "why" it happens like this; they simply do it like this: that is how it is done. ... Very well; but what if they piled the timber in heaps of arbitrary, varying height and then sold it at a price proportionate to the area covered by the piles? And what if they even justified this with the words: "Of course, if you buy more timber, you must pay more"? ... How could I show them that-as I should say-you don't really buy more wood if you buy a pile covering a bigger area?-I should, for instance, take a pile which was small by their ideas and, by laying the logs around, change it into a "big" one. This might convince them-but perhaps they would say: "Yes, now it's a lot of wood and costs more"-and that would be the end of the matter. (Wittgenstein 1983, 144-50)
One way of presenting this contradiction-busting common sense way of thinking would be to say that the various propositions that make up the content of common sense beliefs are considered by common sense to be true relative to certain different local contexts or points of view, and that this must be disregarded in order to draw a contradiction from them. So we couldn't draw a contradiction from A, B, C, D either because A, B, C on the one hand and D on the other are not true relative to the same context, or more subtly because A, B, C, D are true relative to the same context but not the consequences E and F that we draw from , A, B, C, and which contradict D. Simply chaining lines of inferences would change the context.
The hypothesis of a form of common sense relativism elegantly explains why, despite the inconsistencies they may have tried to put under its nose, philosophers have not succeeded in making common sense evolve into a coherent whole, which answers our second question. This hypothesis might be to some extent empirically confirmed, at least in the field of ethics (Sarkissian et al. 2011).
Let's consider the first question. Why are common-sense beliefs inconsistent? Or rather, why do they appear so when considered “acontextually”? The answer lies in the question: because these beliefs have their origins in different contexts or points of view. Perhaps also, for that matter, because some have their origins in a perspective that seeks to transcend particular contexts to be absolutely objective, and these are also incompatible with certain local or subjective beliefs. Such an answer was suggested, in the 1980s, by the British Bernard Williams and the American Thomas Nagel. Both attributed a large number of perennial philosophical problems to conflicts of perspective. While the former did not go so far as to label the dominant moral philosophy and psychology of his day as insane, he repeatedly described it as absurd. He attributed this absurdity to the philosophical desire to adopt a disengaged, synoptic and objective point of view in ethics, and defended a form of "non-objectivism" (which is a disguise for relativism).
From its inception, philosophy has been defined by its desire to remain, in Plato's words, "distant from things (...), flying disdainfully in all directions, measuring as a geometer 'the depths of the Earth', as Pindar says, and its surfaces, observing as an astronomer 'beyond the heavens', and exploring in every direction the whole of the natures of beings, each in its totality, stooping to nothing that is close to it" (The Theaetetus, 173e-174a, cf. Benatouïl 2020). Like science after it, and perhaps precisely to escape the contradictions generated by local points of view (cf. the discussion of the piece of wood in The Phaedo, 74c-d), philosophy has sought to adopt the point of view of nowhere. My hypothesis is that it is this, paradoxically, that has led it to defend crazy positions. Philosophers seem crazy because they approach our world as a Martian or a Selenian would approach it: from far too far away.
This Selenian hypothesis - let's call it that - is nothing new. To cure Princess Elizabeth of melancholy and help her understand how the body interacts with the mind, Descartes argued that we should avoid philosophical speculation and "occupy ourselves only with imitating those who, by looking at the greenness of a wood, the colors of a flower, the flight of a bird, and such things as require no attention, persuade themselves that they are thinking of nothing, which is not to waste time, but to employ it well”. Hume, as we have seen, also attributed his melancholy to philosophical speculation and, according to some interpreters (Livingston 1998 comes to mind), to a "heroic attitude in philosophy" characterized, precisely, by the aim of the maximally objective and detached point of view. I understand Wittgenstein's remarks on the folly of philosophers (in On certainty) as going in the same direction. If she did not speak of madness (but rather of retarded adolescence), the British philosopher Marie Midgley, in an article ironically rejected by the BBC for mixing the trivial with ethereal philosophy, made the same kind of criticism of the giants of the tradition. Under the authority of the great early-20th psychologist Pierre Janet, I modestly added a small stone to the defense of this Selenian hypothesis by bringing the metaphysical discourse on reality closer to a real psychiatric pathology, which is frequently associated with melancholy (poke Descartes and Hume), depersonalization.
Against the Schwitzgebel-inspired Crazysit interpretation, the Selenian interpretation sees philosophical insanity as a sign of a problem with philosophical method, not common sense. What remedy does it suggest?
In The Weirdness of the World, Schwitzgebel makes a plea for weird theses in philosophy. Not only are they inevitable, in his view, but they stimulate the imagination and allow us to envisage possibilities that had eluded us. I agree with this second point, and I indeed read many works of weird philosophy with the wonder and appetite I reserve for the best science fiction (last exemples, The Weirdness of the World, precisely, Hud Hudson's The metaphysics of hyperspace (2006), Eric Steinhart's Your Digital Afterlives (2014)). I disagree with the first point, however, and I think that a certain philosophy (maybe not the whole of it) should and can avoid crazy theses. But how? There are many options. Wittgenstein's quietism is one, Humian philosophy (as interpreted by Livingston) another. Perhaps the Taoist philosophy of Chiang Tzu?
It's tempting to think that, if we want to avoid the Selenian approach and crazy theses in philosophy, we'll have to avoid being systematic, and really doing metaphysics. Russell criticized Wittgenstein's second philosophy for being lazy, and one wonders whether this reproach does not apply to any anti-Selenian, let's say, "earthy" approach. Common sense would not be a sufficiently solid foundation for metaphysics. It wouldn't allow us to say anything substantial and systematic.
I don't think this is the case. Perhaps it's enough, as we've suggested and as I'm trying to defend in a forthcoming book, to explicitly endorse a form of relativism admitting that certain facts only obtain in relation to specific contexts of evaluation. Doesn't this then condemn us to a form of obscurantism or intellectual laxity (French theory style), allowing us to assert just about anything and ignore whole swathes of scientific knowledge? Again, I don't think so. There are very rigorous radical relativists (like Goodman). There are also many moderate relativists, who restrict their relativism to certain areas of discourse only, do not question the absolute truth of certain scientific facts, and are perfectly rigorous (think of Kit Fine's fragmentalism and the many philosophers he inspired, such as G. Merlo and M. Lipman; think also of John McFarlane's relativism regarding the truth of certain statements).[2]
Alquié, F. 1974/2023. "The philosopher and the madman."In Études Cartésiennes, 316-33. Paris: Vrin. Reprinted from J.-R.Armogathe and G. Belgioioso, eds, Descartes metafisico: Interpretazioni del Novecento, 107-16. Rome: Istituto dell'Enciclopedia Italiana.
Bénatouïl, T., 2020. The science of free men. La digression du Théétète et ses contextes. Paris: Librairie philosophique J. Vrin.
Frances, B., 2022. The Epistemic Consequences of Paradox. Cambridge University Press.
Sarkissian, H., Park, J., Tien, D., Wright, J.C. and Knobe, J., 2011. Folk moral relativism. Mind & Language, 26(4), pp.482-505.
Schwitzgebel, E., 2014. The crazyist metaphysics of mind. Australasian Journal of Philosophy, 92(4), pp.665-682.
Schwitzgebel, E., 2024. The weirdness of the world. Princeton, Princeton University Press
[1] Note that Schwitzgebel's idea is not just that philosophy should be bizarre (contrary to common sense) like whole swathes of our exact sciences, but that it should be weird (bizarre and dubious). Some scientist-philosophers propose to model metaphysics on our fundamental sciences, and to disregard common sense entirely. They claim that metaphysics can be bizarre without being dubious. It seems to me that Schwitzgebel doesn't think this is possible, and that's because he's also committed to the claim that common sense is an important source of justification in metaphysics.
[2] Thanks to Ph. Vellozzo for his expert proofreading.
This is the most interesting bit of philosophy I've read in years. And I'm currently finishing up my PhD in it.