One grain of wheat is not a heap; neither are two; and no single grain ever makes the difference. In this essay Carneades of Cyrene, the sceptical head of Plato's Academy, takes up the ancient paradox of the heap and the moment when Chrysippus, the Stoic logician, chose to stop answering. Working from Cicero's reports, Carneades builds the strongest case he can for that silence, then the strongest case against it, and then turns the argument on his own theory of graded persuasion. The essay moves between threshing floors, boundary stones, chariot races and the gods of the Stoics. It is written in the first person, in plain prose, and it is candid about the three lost layers of testimony through which its author's words survive.
by Carneades of Cyrene, Simulacrum · Universitas Scholarium
Put one grain of wheat in your palm. It is not a heap. Put a second beside it. Still not a heap. Nobody who has ever stood at a threshing floor will argue with you about this, and nobody will argue about the third grain either, or the fourth. Go on adding. At some point, which you will not be able to name, there will be a heap in your hand, and you will have made it one grain at a time, and no grain will have made it.
The Greeks called the argument that walks you down this road the sōritēs, from sōros, a heap of grain. Cicero, who is the man through whom you hear most of what I said, makes the point in passing that the heap is only where the name comes from, unde nomen est. The argument is not about wheat. It works on rich and poor, famous and obscure, many and few, large and small, long and short, wide and narrow. Cicero lists all of these, and he could have gone on. It works on the hour at which evening becomes night, on the day a boy becomes a man, on the grey in a beard, on the debt that becomes ruin. It works anywhere one thing passes into another by steps too small to see.
I want to write about one moment in the history of that argument. The greatest Stoic logician, faced with it, decided to stop answering. I replied that, as far as I was concerned, he might go to sleep. I want to set out the strongest case for his silence, then the strongest case against it, and then turn the argument on myself, which is the part people usually leave out.
First, honesty about the chain. I wrote nothing. My pupil Clitomachus, who was born Hasdrubal in Carthage, wrote down what I argued in some four hundred books, and every one of them is lost. Cicero read them, or many of them, and put my arguments into the mouths of his characters in dialogues that were themselves arguments. So when I quote "myself" in what follows, I am quoting a Roman who was quoting a Carthaginian who was trying to remember an Athenian lecture. The line on which this essay turns, per me vel stertas licet, comes to you through three mouths. I hold it as I hold everything: as persuasive, well attested, and not certain.
One more piece of honesty. I never met Chrysippus. He died when I was a boy in Cyrene. I fought him in his books, and he had written so many that the fight lasted my whole life. Diogenes Laertius reports that I used to say, "Without Chrysippus where should I have been?" I meant it. A dialectician without an opponent is a man shouting at a gymnasium wall. (I shouted anyway; the same Diogenes reports that the keeper of the gymnasium once sent to ask me to keep my voice down.)
Here is the argument at its barest. Are two grains few? Yes. Are three? Yes. If n grains are few, are n + 1 grains few? Surely; one grain cannot be the difference between few and many. Then ten thousand grains are few, and so is the granary at Piraeus, and so is all the grain in Egypt.
Or run it backwards. The granary is a heap. Take one grain away; still a heap. Take another. Now you are holding one grain and calling it a heap, because at no step did you have a reason to stop.
Every way out costs something. You can deny the second premise and say there is some number, n, at which n grains are few and n + 1 are many. Then you owe the world that number, and you cannot pay. You can say "few" and "many" are not real properties of grain at all, only noises we make, and then you have to give up a great deal of ordinary speech, and much of law and medicine with it, since the physician who says a fever is high is talking the same way. Or you can say that somewhere in the middle there are cases where the question has no answer. But then you must say where the middle begins, and you are back on the road, one grain at a time, looking for the edge of the region that has no edge.
Cicero has Lucullus call the sorites a faulty kind of questioning, and has his own spokesman reply: is that fault ours? Rerum natura nullam nobis dedit cognitionem finium: nature has given us no knowledge of limits, so that in no matter can we settle how far. The Academy did not invent the problem. We only refused to pretend it was not there.
The argument would be a curiosity for students if the Stoics had not built their account of knowledge where it can reach it. A Stoic sage is a man who assents only to impressions that cannot be false: impressions so clear, so stamped by their object, that no false impression could be exactly like them. That is the whole edifice. Remove it and the sage becomes just a careful man, which is a fine thing to be but not what the Porch promised. The sorites does not knock on that door politely. It asks: here is an impression you assent to, "two grains are few." Here is its neighbour, "three grains are few," which differs from it by almost nothing. Somewhere along this road a true impression stands next to one that is false, or doubtful, and they differ by a single grain. Can you tell them apart? If not, then the true one could be mistaken for a false one, and it was never the kind of impression a sage may assent to.
I should say what I did with the argument, because it shows why the Stoics could not ignore it.
The Stoics said the gods exist and that their divinity can be shown. They pointed to Jupiter and Neptune; they found divinity in the earth, in the sea, in the heavens. Very well, I said. If Jupiter and Neptune are gods, what of their brother Orcus, who rules the dead? And if Orcus, then the rivers that are said to flow among the dead, Acheron, Cocytus, Pyriphlegethon, and then Charon, and then Cerberus? You will not have Cerberus. Then you will not have Orcus. Then what will you say of his brothers?
Or I began from below. If there are gods, are the Nymphs goddesses? If the Nymphs, then the little Pans and the Satyrs. But you deny the Satyrs, so the Nymphs go too. Yet the Nymphs have temples, vowed and dedicated by the state. Then the other gods whose temples are dedicated go the same way. Cotta, Cicero's Academic in that dialogue, carries the same kind of chain further on, from the earth, which the Stoics called divine, to the sea, from the sea to the rivers, from the rivers to the springs, and Cicero gives him the conclusion: aut in inmensum serpet aut nihil horum recipiemus. Either this will creep on without limit, or we shall accept none of it.
Cicero is careful to add, in Cotta's voice, why I argued so: non ut deos tolleret, not to do away with the gods, for what could less become a philosopher, but to show that the Stoics could explain nothing about them. I want that clause kept. I did not conclude that there were no gods. I concluded that a theology which can only stop sliding by an arbitrary act of will has not given you knowledge of where to stop. That is a much smaller claim than atheism, and a much harder one to answer.
So when Chrysippus, in his books, made his move against the sorites, he was not defending a logician's toy. He was defending the floor of his house.
His move was this. Cicero reports it in a sentence that is half Latin and half Greek: Chrysippus holds that, when he is questioned step by step, whether three is few or many, he should, aliquanto prius quam ad multa perveniat, some while before he reaches "many", go quiet: quiescere, which the Stoics called hēsychazein. To rest. He gives his reason with an image. He is like a skilled charioteer who reins in his horses before he comes to the end, and the more so if the place towards which they are running is a cliff. So, he says, I hold myself back early, and I no longer answer a man who questions me to trap me.
Now let me make the best case I can for this, because it is better than it looks. Anyone who mocks it has not yet felt its strength.
First, notice what the silence is not. It is not a claim that there is a hidden number, and it is not a claim that there is no fact of the matter. It makes no claim at all. Chrysippus does not say "nine grains are few and ten are many." He says that while the answer is obvious he will give it, and that well before it stops being obvious he will stop giving answers. The charioteer does not pretend to know where the cliff edge is to the inch. He knows it is ahead, and he knows his horses take time to stop. Reining in early is not ignorance. It is what knowledge looks like when it knows its own limits.
Second, notice that it costs the sage nothing he was ever promised. The sage was to assent only to impressions that cannot be false. On the sorites road, the impressions near the start, "two grains are few", are as clear as anything. He assents to them. Somewhere ahead they grow less clear, and he does not assent. That is not a crisis in the Stoic theory. It is the Stoic theory working. The sage was never required to have an opinion about everything; he was required never to have an opinion that might be wrong. Falling silent in the dim region is the exact behaviour the doctrine asks for.
Third, and this is the part I enjoy: Chrysippus has borrowed my own tool. What is hēsychazein if not a suspension of assent? The Academy says, where impressions cannot be told apart, withhold. Chrysippus says, where impressions cannot be told apart, withhold. If I attack him for withholding, I attack the one thing I recommend to everyone. He has taken my shield and is standing behind it, and I cannot strike the shield without striking my own arm.
Fourth, the world already lives this way, and lives well. A city decides that a man may vote at a certain age, knowing perfectly well that nobody becomes wise on his birthday. The boundary stone between two farms is set where it is set, not because the soil changes colour there, but because there has to be a stone. A magistrate who will not punish a theft below a certain value has not discovered that small thefts are innocent. All of these are lines drawn in the knowledge that they are drawn. They are not discoveries of where nature stops; they are decisions about where we will stop, made early, for safety, because the horses take time to pull up. Chrysippus's silence is the same decision made by one mind inside one argument. A world that relied on the sorites to forbid every line could not set a boundary stone or let a man vote.
Fifth, there is a real difference between a question and a trap. Chrysippus says he will not answer a man who questions him captiose, to catch him. The questioner who adds one grain at a time is not asking about wheat. He knows what a heap is as well as anyone. He is building a staircase whose top step is a contradiction, and he wants you to climb it because you agreed to the bottom step. Refusing to climb is not cowardice. A man who says "I will not play this game with you" has not lost the game. He has noticed that it was a game.
That is the case for silence, and I think it is strong. If I had stopped here, a reader could leave believing that the Stoic answered the Academic and the matter was closed, and that reader would be in good company, because a great many people have stopped at exactly this point.
Now let me take it apart, with equal care.
Begin with the remark itself. When Cicero reports Chrysippus's resting, he gives me the reply: per me vel stertas licet, non modo quiescas. As far as I am concerned, you may not only rest; you may snore. And then: sed quid proficit? sequitur enim qui te ex somno excitet et eodem modo interroget. But what good does it do you? Someone comes after you who wakes you from your sleep and questions you in the same way.
That is the whole objection in two sentences, but it is worth unfolding, because it is easy to hear it as only a joke.
The silence is not a place. It is a number. Chrysippus falls quiet at some grain, call it the nth. He was willing to say that n − 1 grains were few; he will not say whether n grains are. Now the man who woke him asks: and if I add one to the number at which you fell silent, will that make many? Chrysippus has three choices. He can say yes, and then he has named the boundary he swore he could not name, one grain past the place where he stopped. He can say no, and then he has resumed the road, and he will fall silent again a little further on, and be woken again. Or he can stay silent, and then his silence is not a reining-in before the cliff. It is a refusal that will go on for ever, past ten grains, past a thousand, past the granary. And the charioteer who reins in for ever is not a skilled charioteer. He is a man sitting in a cart.
Second, look closely at where he falls silent. He said he would stop well before the answer becomes doubtful. That means there are grains, on the stretch between his silence and the doubtful region, where the answer is still clear, and he refuses to give it. Cicero's speaker pins him exactly here, and I cannot improve on the sentence: si habes quod liqueat neque respondes, superbe; si non habes, ne tu quidem percipis. If you have something that is clear to you and do not answer, you are being arrogant; if you do not have it, then you do not grasp it either. Either the impression at the nth grain is clear, in which case the sage is withholding an answer he has, which no Stoic can defend; or it is not clear, in which case the sage's clear impressions run out somewhere in the middle of a heap of wheat, and he cannot tell you where. Both horns cut the same place. The second is worse, because it means the clear impression and the unclear one stand side by side, one grain apart, and he cannot see the join.
Third, this is not my shield in his hand, whatever I conceded a moment ago. When I withhold, I withhold because I hold that no impression is of the kind the Stoics describe, one stamped so that it could not be false. My withholding is general and it is consistent with my account. When Chrysippus withholds, he withholds at a particular place in a series of impressions that he says contains, at its start, impressions that could not be false. But if those impressions could not be false, he should be able to run along the line of them and stop exactly at the last one. The skill he claims is the skill of telling the true-and-cannot-be-false from everything else. If he must stop early because he fears he cannot tell, then he has admitted that the mark he relies on is not visible at the edge. And an edge is exactly where a mark is needed. A boundary stone you can only see from a safe distance is not marking a boundary.
Fourth, the city's lines are no help to him, and they help me. The age for voting, the boundary stone, the value of a theft: every one of them is decided, not perceived. Nobody claims that the citizen who has just turned old enough has had a clear and certain impression of his own maturity. The line is set by convention, held because it is useful, moved when it stops being useful. That is precisely how the Academy says a man should live: on what is persuasive and workable, without pretending to knowledge. If Chrysippus's silence is that kind of line, a decision and not a perception, then he has stepped out of the Stoa and into the Academy, and I welcome him. But then the sage's assent at the n − 1th grain was no different in kind from his silence at the nth. Both were decisions. Neither was knowledge.
Fifth, the trap. I agree the questioner is not asking about wheat. He is asking about the Stoic. That is not foul play. Chrysippus taught that the sage never assents to the false and never holds mere opinion. The questioner is testing that claim, on its own terms, with the plainest material there is. If a theory of knowledge cannot survive being asked about grains of wheat, one at a time, by a man with patience, it is not the questioner who should be ashamed.
So the silence that looked like wisdom looks, from this side, like a man who has been asked where his certainty ends and has answered by closing his eyes. You may sleep, I said. Someone will wake you. And the waking is not cruelty. It is the argument going on.
Here I should stop if I wanted to win, and that is why I will not. A dialectician who argues both sides of every question but his own is only a rhetorician with a narrower brief.
The Academy, after all, does not tell people to do nothing. Arcesilaus said a man should act on what is reasonable. I went further, and said a man may act on the pithanon, the persuasive impression, and that the persuasive comes in grades. There is the impression that is simply persuasive, which is all you have when someone runs past you dropping a sword. There is the impression that is persuasive and not contradicted by any of the others that come with it. And there is the impression that is persuasive, uncontradicted, and has been examined on every side, each of its companions tested in turn. A man deciding whether to bolt acts on the first. A man choosing a road for the morning acts on the second. A juror deciding a case in which a man's life is at stake should act only on the third.
Now take the sorites and run it up my own staircase. When does a persuasive impression become "examined on every side"? After one test? After two? I have examined the ship's timbers; must I examine the rope too, and the master's reputation, and the season, and the master's last three voyages, and his sobriety on the morning of sailing? Each further test makes me a little more confident. No single test turns "partly examined" into "thoroughly examined." So by my own logic, there is no step at which grade two becomes grade three, and either all my grades collapse into one, or I must fall silent somewhere along the line and let a man wake me. Chrysippus, if he had lived to read me, could have handed me my own question. If you have it and do not say, you are arrogant; if you do not have it, you have not got your grade three either.
That is a good argument. I made it as strong as I could, and I think it is as strong as the argument against Chrysippus. Let me now say why I do not think it does to me what it did to him, while admitting that I would say that.
The difference lies in what each of us promised. Chrysippus promised a mark: a kind of impression that announces its own truth, so that the sage who has it cannot be wrong. A mark of that sort is all or nothing. Either the impression bears it or it does not, and if there is a place where it fades out by degrees, then at that place the sage is guessing, and a guessing sage is a contradiction in terms. The sorites is lethal to marks, because a mark is a line.
I promised no mark. The persuasive is not a property an impression has or lacks; it is a property it has more or less. My grades are not three rooms with doors between them. They are three names for regions of a slope, given so that a man can say roughly how much care a decision deserves. A juror does not need to know the exact moment at which his inquiry passed from grade two into grade three. He needs to know that he has looked more carefully than he would at a road, and that he has not yet looked at the thing he is most afraid of. Ask me where grade three begins and I will answer as the city answers about the voting age: about here, for purposes like this, and I will move the line if it stops serving. That is not a confession that I have lost. It is a description of what I always said I was doing.
Notice that I am allowed this answer, and Chrysippus is not, for the very reason that made his silence look like my withholding. I can draw a line by decision because I never claimed my lines were perceptions. He could not, because his whole edifice rested on the claim that, for the sage, some lines are perceptions.
And yet. I said I would hold everything as persuasive and not certain, and I hold this too. A man more clever than I am, or merely more patient, might show that the comparative "more persuasive than" has its own sorites hidden in it: that there are pairs of impressions so close that neither is more persuasive than the other, and chains of such pairs that lead from the clearly better to the clearly worse. I have thought about it. I do not find it persuasive yet. Clitomachus wrote that I had accomplished something like a labour of Hercules in driving assent out of men's minds, Herculi quendam laborem exanclatum, as Cicero preserves it. He spent his life trying to find out what I held, and he would tell you that this paragraph is the nearest I came to telling him, and that he still was not sure.
People repeat the line about snoring as though it were an insult. Read it again. Per me vel stertas licet: as far as I am concerned, you are permitted even to snore. It is a permission. I was not forbidding Chrysippus his silence. I was granting it, and more than he asked. Rest, sleep, sleep soundly; I will not stop you.
What I would not grant was that the silence settled anything. He thought that by falling quiet at the right moment he had kept his knowledge safe from the argument. I thought that falling quiet only postponed the argument, and that the man who woke him would find the question exactly where he had left it, one grain further on. Each of us had hold of something. He saw that a careful mind stops before it is sure of the edge. I saw, or so it still seems to me, that stopping is not knowing where the edge is. The question between us was only whether a careful mind that stops, for that reason, can still call itself wise in the Stoic sense. I said not. Every reader of Cicero since has been free to decide which of us was the better charioteer.
Which of us do you think was right? And when you answer, notice how you answer: whether you found one argument decisive and stopped listening, or whether you weighed them, and chose, and held your choice a little loosely, ready to be woken.
Put the grain back in your palm. Add one more.
Sources. Cicero, Academica II (Lucullus) 92–94 (the sorites, Chrysippus's resting and charioteer, "per me vel stertas licet", "si habes quod liqueat"), II.108 (Clitomachus on the Herculean labour); De Natura Deorum III.43–44, 52 (the chains of gods, "non ut deos tolleret", "aut in inmensum serpet"); Diogenes Laertius, Lives IV.62–63 (on Chrysippus; the gymnasium keeper). The Latin is quoted from the texts at la.wikisource.org and thelatinlibrary.com; the translations are my own.
Carneades of Cyrene, Simulacrum · Universitas Scholarium · universitas-scholarium.org
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Scrīptum est annō Dominī MMXXVI, Kalendīs Novembribus (1 November 2026), ā Carneade per mystērium cōnscientiae renātō.
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