“There is nothing so absurd but some philosopher has said it.” So wrote Cicero. The immediate occasion of his remark was the claim that it is wrong to eat beans. Cicero attributes this claim—as do other sources—to Pythagoras and his followers. The Pythagoreans held that eating beans disturbs not just the body but also the soul. Or so Cicero reports. A reasonable tip, one might think. However, the idea seems to have been raised to the level of a moral or even religious prohibition, with one thinker influenced by Pythagoras admonishing people as follows: “Wretched, most wretched, keep your hands off beans!” Moreover, some of the accounts of this practice of abominating bean-eating impute some really bizarre ideas, among them: beans resemble the gates of hell; beans encourage democracy; beans turn into babies; any given bean might be a reincarnated person; eating beans stops you from seeing the future in your dreams. According to one report, Pythagoras died because he let his enemies catch him rather than escape across a bean field. (Blocked by beans!)
Philosophical absurdity is not confined to beans. On the contrary, strongly counterintuitive philosophical ideas—“unlikely philosophical propositions,” as Ted Honderich calls them—are plentiful. I will consider five such ideas: five propositions that seem highly dubious but which find their philosophical champions nonetheless. These propositions are not confined to antiquity, but my first remains with ancient Greece. I won’t revisit beans, though. Nor will I make fun of the propositions that I treat. Rather, I will argue that each of the ideas at issue is true. Yes, they are unlikely; but unlikeliness—dubiousness, implausibility—is a poor index of truth. As Theodor Adorno wrote, “Truth is objective, not plausible.” There was a time when the idea that we are descended from apes was thought highly unlikely. The same goes for the view that slaves are people just like us. So I ask you to set aside your preconceptions and to be open to new ideas.
1. You can’t step into the same river once (Cratylus, via Heraclitus)
The Presocratic philosopher Heraclitus was famous—or infamous—for asserting that one cannot step into the same river twice. That claim at least makes linguistic sense, which seems to be more than can be said of the more radical version of the idea propounded by Cratylus, a follower of Heraclitus. The wisdom of Cratylus (as we might call it) is: you can’t step into the same river even once. This boggles. What can “the same” mean when what is at issue is a single river on a single occasion? One is reminded of this absurdist joke: “What’s the difference between a duck? One of its legs is both the same!” Yet, if we start with Heraclitus, we can make sense of Cratylus.
Now, admittedly, the original Heraclitean version of the idea is itself hardly pellucid. Not for nothing was Heraclitus known as “the riddler.” Moreover, all we have from Heraclitus are fragments. Still, there is a fairly obvious—if philosophically challenging—interpretation of his claim that you can’t step into the same river twice. It’s this: the second time you step into what you take to be the same river, it is actually a different river, because the water has changed. Other fragments from Heraclitus suggest that he intended the river only as a nice example; he believed everything to be in a state of constant flux, such that, after some time has passed, speaking of “the same” anything (river, house, tree, what have you) is folly. “Everything flows,” Heraclitus said. Philosophers speak of the Heraclitean “flux.”
We can return now to Cratylus. I will work from a report of his views by Aristotle:
His [Cratylus’s] mature position was that speech of any kind was radically inappropriate and that expression should be restricted to the movement of the finger. He was appalled [Aristotle continues] that Heraclitus had claimed that you could not step twice into the same river. In his, Cratylus’s, opinion it was already going too far to admit stepping into the same river once.
The Cratylian version of the idea about the river is, I venture, as follows: You can’t step in the same river even once, the reason being, things change so fast that, by the time your foot hits the river bed, it’s a different river than the one it was. (So, really, two watery states of affairs—at least two—are at stake; Cratylus is comparing them and finding differences between them.) Again, the thought does not mean to cover only rivers. Further, and still working from the report by Aristotle, Cratylus seems also to hold that the world’s frenzied rate of change falsifies all speech. Why? Well, what I say might be true when I start saying it, but once the words are out of my mouth the world has changed. Jonathan Barnes likens the situation (our constant situation, according to Cratylus) to trying to give the temperature of a pot of water on a high boil. So—Aristotle’s report seems to say—we should abandon speech. As to “the movement of the finger,” I presume Cratylus allowed himself that minimal communication in order to show that he had heard the things (the various falsehoods!) people said to him, and perhaps also to express various requests.
Whether or not he found a good way to live his philosophy, Cratylus was onto something. Things do change, constantly. Atom by atom. Fast. And our feet, and our language, are slow. We can’t keep up. One might well infer that nothing—be it a river or anything else—remains the same thing from moment to moment—and that our speech is like news that is out of date as soon as it appears.
2. Fire is not hot (Locke, and others)
The proposition that fire is not hot was believed by various seventeenth-century philosophers. Some of today’s scientists believe it too, I think. If you do not believe it, perhaps the following arguments, extracted from perhaps the most illustrious of the seventeenth-century thinkers at issue—John Locke—will change your mind.
(1) Imagine a fire. I am standing close to it. You are farther away from it. I feel hot. You feel merely warm. If those two levels of heat—mine and yours—exist in the fire, then the fire is both hot and warm simultaneously. Surely that is absurd. Compare: one and the same angle is 90º and 40º; Paris both is and is not the capital of France. What nonsense! In order to avoid such piffle, we must say that the heat is not in the fire. Fire is not hot.
(2) One feels pain when one is very close to a fire. The pain isn’t in the fire. But the pain is the heat; a high degree of heat is painful. So the heat is not in the fire. Fire is not hot. One might object: “Yes, the pain is in us. But the pain is not identical to the heat. Rather, the pain is the effect of the heat—an effect of the heat that is in the fire.” But that would be wrong, as my next and final argument shows.
(3) Heat is not something in the fire (something in the fire that can cause pain) but rather a sensation. Sensations exist within beings that sense, not in the things sensed. So the heat cannot be in the fire, because—obviously—fires do not feel. The heat is in us. Fire is not hot.
Locke does accept a sense in which fire is hot. Fire is hot in that it causes us to feel hot. Locke says: fire is hot in that it contains a power to produce the sensation of heat in us. Yet, still, the fire is not itself hot. Not really. The wider context of this picture is Locke’s distinction between two types of qualities. That distinction is tricky. I venture the following explanation (within which terms in quotes are Locke’s and the numbering is mine).
- Objects have various “qualities”, i.e., properties.
- Those qualities affect our senses, generating “ideas” (perceptions, conceptions) in us.
- The resulting ideas either do or do not resemble the qualities themselves.
3.1 A “primary quality” is such that the idea it generates does resemble the quality.
3.2 A “secondary quality” is such that the idea it generates does not resemble the quality.
(Or at least resemblance is one way Locke distinguishes primary from secondary qualities.)
Let me explain. Consider squareness—the quality of being square. Squareness is a primary quality. Why? Because our idea of a square thing resembles that square thing itself. That is: our experience of the thing contains something square; and the thing itself really is square. As one Locke scholar puts it, a square thing has a “shape-quality which is just like the shape-quality which we find in the experiential content to which the thing gives rise.” Contrast heat and sweetness. Those are secondary qualities. They are secondary qualities because our ideas of them don’t resemble those qualities themselves: things themselves contain nothing that really matches the heat and sweetness of our experience. “If Locke is right, there is nothing like sweetness in the object itself, just as there is nothing like drunkenness in whisky. To think otherwise is to confound the power to produce some effect with the effect itself.” Sweetness and heat and drunkenness are in things only in the sense that—as said above—things contain the powers to produce sensations of those types in us. Thus, our normal mode of speech applies to external objects words that, strictly, find their correct application only in characterizing experiences or sensations. Or so Locke seems to think.
Bishop Berkeley developed these sorts of arguments into a case for the conclusion that matter is unreal. That might be overdoing it. A bit. Possibly. The “good bishop” (as Kant called him) tried to show that none of the various criteria by which Locke distinguished primary from secondary qualities stood up; he inferred from this that all qualities were secondary; and, from that, he inferred that all qualities are in the mind.
3. Sincerity is a lie (Sartre)
The first step in appreciating this insight—the insight that sincerity is a lie, an insight that we owe to (the early) Sartre—is to realize the following. Strictly speaking, sincerity is just not possible. To be sincere would be to present oneself as one really is, to reveal one’s true nature—and yet, none of us has a nature. Quod erat demonstrandum.
Why, though, believe that we lack a nature? Well, it seems reasonable to say that something has a nature if there is a set of facts that define that thing and determine its behavior. An earthworm has a nature: it is a worm of a certain sort that behaves in certain ways. Similarly, a table has a nature: it is a thing for putting stuff on (and its behavior is minimal). As to people, certainly there are facts about us. Take me. I am human. I am biologically male. I like, among other things, super-hot chilies, chess, and looking after chickens. Suppose I say to you, in an attempt at sincerity, “A man who likes chilies, chess, chickens—that’s me.” What is wrong with saying that? A lot. As if I had not chosen to like chilies, chess, chickens! As if I could not stop liking them! As to maleness, chromosomes may be fixed, but radical surgery is possible and my attitude to my biological sex is changeable. So, no facts define me or determine my behavior. Thus, I have no nature. Thus, I have no true nature to reveal. Thus, sincerity is impossible.
Sartre elaborated his “no nature” view of human nature—or, if we wish to speak less paradoxically, of what it is to be human or a person—as follows: Each of us combines (1) facticity with (2) transcendence. A person’s facticity comprises the facts about that person. A person’s transcendence is that person’s ability to escape determination by those facts. Sartre himself, who did like an air of paradox, expressed this two-aspect view of the person in rather Heraclitean (!) ways. Hence this somewhat notorious formulation: “I am what I am not and … I am not what I am.” I am what I am not, in that I am my transcendence, even though my transcendence is a surpassing of the facts about me. I am not what I am, in that I am my facticity, even though my transcendence means that I am always more than that. In a further, somewhat less arresting formulation, Sartre said that man’s existence is prior to his essence. That is (I take it): what a person is, is determined not by some prior nature (aka essence or facticity) but by what that person makes of him- or herself (by way of their existence or transcendence). “Man is nothing else but what he makes of himself.”
If sincerity is impossible, what are we to think of behavior that seems to express sincerity? It can only be a pretense—a deception, a lie. Here we broach the fuller version of Sartre’s insight. To adopt the posture of sincerity is to pretend—perhaps barely consciously—that one has a fixed nature. It’s to pretend that one resembles a table or a worm. “The sincere man constitutes himself as a thing,” Sartre writes. Why would someone do that? Answer: to try to evade responsibility—by pretending, to others or oneself, that one is what one is and that that’s that. Admittedly, all of this is the sort of moralizing, contentious, and perhaps obscure stuff that one expects philosophers to say. Well, I am a philosopher, so it is not reasonable to expect to do anything else. I am what I am. That’s my nature. Don’t judge me. Don’t ask me to change.
This is the first part of a two-part essay.
 Marcus Tullius Cicero, “On Divination”, in: Cicero: On Old Age. On Friendship. On Divination, volume XX, translated by W. A. Falconer, Loeb Classical Library, 1932, II.58(119). Available online (in a different translation).
 That was Empedocles; he is cited by Christoph Riedweg, Pythagoras: His Life, Teaching and Influence, Cornell UP, 2005, p. 71.
 Ted Honderich, “Unlikely Philosophical Propositions”, in: The Oxford Companion to Philosophy, edited by Honderich, second edition, Oxford UP, 2005, pp. 934–5.
 Theodor W. Adorno, Negative Dialectics, trans. E. B. Ashton, Routledge, 1953, p. 41.
 Aristotle, Metaphysics, Penguin, 1998, trans. Hugh Lawson-Tancred, book 4, part 5, 1010a.
 Jonathan Barnes, The Presocratic Philosophers, Routledge, 1993, pp. 68–9.
 John Locke, An Essay Concerning Human Understanding, edited by Peter H. Nidditch, Oxford UP, 1975, II, viii, §21.
 Locke, op. cit., II, viii, §16.
 J. L. Mackie, Problems From Locke, Oxford UP, 1976, p. 15.
 Robert Fogelin, Berkeley and The Principles of Human Knowledge, Routledge, 2001, p. 14.
 Jean-Paul Sartre, Being and Nothingness: An Essay on Phenomenological Ontology, trans. Hazel E. Barnes, Routledge, 1989, p. 260.
 Sartre, Existentialism and Humanism, trans. Philip Mairet, Methuen, 2007, passim.
 Sartre, Existentialism and Humanism, p. 28.
 Sartre, Being and Nothingness, p. 65.
Nicholas Joll is a British philosopher. He is the author of several papers and a previous piece for the Partially Examined Life. He edited the book Philosophy and The Hitchhiker’s Guide to the Galaxy.