Testimony about Protagoras

UC Davis Philosophy 21

History of Philosophy: Ancient

Fall, 2004

Instructor: G. J. Mattey, Senior Lecturer


Selections are taken from public-domain translations.


From Plato's Protagoras, 324A, tr. Benjamin Jowett

I have been showing that they are right in admitting every man as a counsellor about this sort of virtue, as they are of opinion that every man is a partaker of it. And I will now endeavour to show further that they do not conceive this virtue to be given by nature, or to grow spontaneously, but to be a thing which may be taught; and which comes to a man by taking pains. No one would instruct, no one would rebuke, or be angry with those whose calamities they suppose to be due to nature or chance; they do not try to punish or to prevent them from being what they are; they do but pity them. Who is so foolish as to chastise or instruct the ugly, or the diminutive, or the feeble? And for this reason. Because he knows that good and evil of this kind is the work of nature and of chance; whereas if a man is wanting in those good qualities which are attained by study and exercise and teaching, and has only the contrary evil qualities, other men are angry with him, and punish and reprove him--of these evil qualities one is impiety, another injustice, and they may be described generally as the very opposite of political virtue. In such cases any man will be angry with another, and reprimand him,--clearly because he thinks that by study and learning, the virtue in which the other is deficient may be acquired. If you will think, Socrates, of the nature of punishment, you will see at once that in the opinion of mankind virtue may be acquired; no one punishes the evil-doer under the notion, or for the reason, that he has done wrong, --only the unreasonable fury of a beast acts in that manner. But he who desires to inflict rational punishment does not retaliate for a past wrong which cannot be undone; he has regard to the future, and is desirous that the man who is punished, and he who sees him punished, may be deterred from doing wrong again. He punishes for the sake of prevention, thereby clearly implying that virtue is capable of being taught. This is the notion of all who retaliate upon others either privately or publicly. And the Athenians, too, your own citizens, like other men, punish and take vengeance on all whom they regard as evil doers; and hence, we may infer them to be of the number of those who think that virtue may be acquired and taught. Thus far, Socrates, I have shown you clearly enough, if I am not mistaken, that your countrymen are right in admitting the tinker and the cobbler to advise about politics, and also that they deem virtue to be capable of being taught and acquired.


From Plato's Protagoras, 377E, tr. Benjamin Jowett

You, Socrates, are discontented, and why? Because all men are teachers of virtue, each one according to his ability; and you say Where are the teachers? You might as well ask, Who teaches Greek? For of that too there will not be any teachers found. Or you might ask, Who is to teach the sons of our artisans this same art which they have learned of their fathers? He and his fellow-workmen have taught them to the best of their ability,--but who will carry them further in their arts? And you would certainly have a difficulty, Socrates, in finding a teacher of them; but there would be no difficulty in finding a teacher of those who are wholly ignorant. And this is true of virtue or of anything else; if a man is better able than we are to promote virtue ever so little, we must be content with the result. A teacher of this sort I believe myself to be, and above all other men to have the knowledge which makes a man noble and good; and I give my pupils their money's-worth, and even more, as they themselves confess. And therefore I have introduced the following mode of payment:--When a man has been my pupil, if he likes he pays my price, but there is no compulsion; and if he does not like, he has only to go into a temple and take an oath of the value of the instructions, and he pays no more than he declares to be their value.


From Plato's Theaetetus, 152E, tr. Benjamin Jowett

SOCRATES: Bravely said, boy; that is the way in which you should express your opinion. And now, let us examine together this conception of yours, and see whether it is a true birth or a mere wind-egg:--You say that knowledge is perception?
THEAETETUS: Yes.
SOCRATES: Well, you have delivered yourself of a very important doctrine about knowledge; it is indeed the opinion of Protagoras, who has another way of expressing it. Man, he says, is the measure of all things, of the existence of things that are, and of the non-existence of things that are not:--You have read him?
THEAETETUS: O yes, again and again.
SOCRATES: Does he not say that things are to you such as they appear to you, and to me such as they appear to me, and that you and I are men?
THEAETETUS: Yes, he says so.
SOCRATES: A wise man is not likely to talk nonsense. Let us try to understand him: the same wind is blowing, and yet one of us may be cold and the other not, or one may be slightly and the other very cold?
THEAETETUS: Quite true.
SOCRATES: Now is the wind, regarded not in relation to us but absolutely, cold or not; or are we to say, with Protagoras, that the wind is cold to him who is cold, and not to him who is not?
THEAETETUS: I suppose the last.
SOCRATES: Then it must appear so to each of them?
THEAETETUS: Yes.
SOCRATES: And 'appears to him' means the same as 'he perceives.'
THEAETETUS: True.
SOCRATES: Then appearing and perceiving coincide in the case of hot and cold, and in similar instances; for things appear, or may be supposed to be, to each one such as he perceives them?
THEAETETUS: Yes.
SOCRATES: Then perception is always of existence, and being the same as knowledge is unerring?
THEAETETUS: Clearly.


From Plato's Theaetetus, 166D, tr. Benjamin Jowett

But, O my good sir, he will say, come to the argument in a more generous spirit; and either show, if you can, that our sensations are not relative and individual, or, if you admit them to be so, prove that this does not involve the consequence that the appearance becomes, or, if you will have the word, is, to the individual only. As to your talk about pigs and baboons, you are yourself behaving like a pig, and you teach your hearers to make sport of my writings in the same ignorant manner; but this is not to your credit. For I declare that the truth is as I have written, and that each of us is a measure of existence and of non-existence. Yet one man may be a thousand times better than another in proportion as different things are and appear to him. And I am far from saying that wisdom and the wise man have no existence; but I say that the wise man is he who makes the evils which appear and are to a man, into goods which are and appear to him. And I would beg you not to press my words in the letter, but to take the meaning of them as I will explain them. Remember what has been already said,--that to the sick man his food appears to be and is bitter, and to the man in health the opposite of bitter. Now I cannot conceive that one of these men can be or ought to be made wiser than the other: nor can you assert that the sick man because he has one impression is foolish, and the healthy man because he has another is wise; but the one state requires to be changed into the other, the worse into the better. As in education, a change of state has to be effected, and the sophist accomplishes by words the change which the physician works by the aid of drugs. Not that any one ever made another think truly, who previously thought falsely. For no one can think what is not, or, think anything different from that which he feels; and this is always true. But as the inferior habit of mind has thoughts of kindred nature, so I conceive that a good mind causes men to have good thoughts; and these which the inexperienced call true, I maintain to be only better, and not truer than others. And, O my dear Socrates, I do not call wise men tadpoles: far from it; I say that they are the physicians of the human body, and the husbandmen of plants--for the husbandmen also take away the evil and disordered sensations of plants, and infuse into them good and healthy sensations--aye and true ones; and the wise and good rhetoricians make the good instead of the evil to seem just to states; for whatever appears to a state to be just and fair, so long as it is regarded as such, is just and fair to it; but the teacher of wisdom causes the good to take the place of the evil, both in appearance and in reality. And in like manner the Sophist who is able to train his pupils in this spirit is a wise man, and deserves to be well paid by them. And so one man is wiser than another; and no one thinks falsely, and you, whether you will or not, must endure to be a measure. On these foundations the argument stands firm, which you, Socrates, may, if you please, overthrow by an opposite argument, or if you like you may put questions to me--a method to which no intelligent person will object, quite the reverse.


From Aristotle's Metaphysics, Book IV, Chapter 4, tr. by W. D. Ross

Again, if all contradictory statements are true of the same subject at the same time, evidently all things will be one. For the same thing will be a trireme, a wall, and a man, if of everything it is possible either to affirm or to deny anything (and this premiss must be accepted by those who share the views of Protagoras). For if any one thinks that the man is not a trireme, evidently he is not a trireme; so that he also is a trireme, if, as they say, contradictory statements are both true.


From Aristotle's Metaphysics, Book IX, Chapter 6, tr. by W. D. Ross

The saying of Protagoras is like the views we have mentioned; he said that man is the measure of all things, meaning simply that that which seems to each man also assuredly is. If this is so, it follows that the same thing both is and is not, and is bad and good, and that the contents of all other opposite statements are true, because often a particular thing appears beautiful to some and the contrary of beautiful to others, and that which appears to each man is the measure. This difficulty may be solved by considering the source of this opinion. It seems to have arisen in some cases from the doctrine of the natural philosophers, and in others from the fact that all men have not the same views about the same things, but a particular thing appears pleasant to some and the contrary of pleasant to others.


From Aristotle's Metaphysics, Book X, Chapter 6, tr. by W. D. Ross

Knowledge, also, and perception, we call the measure of things for the same reason, because we come to know something by them--while as a matter of fact they are measured rather than measure other things. But it is with us as if some one else measured us and we came to know how big we are by seeing that he applied the cubit-measure to such and such a fraction of us. But Protagoras says 'man is the measure of all things', as if he had said 'the man who knows' or 'the man who perceives'; and these because they have respectively knowledge and perception, which we say are the measures of objects. Such thinkers are saying nothing, then, while they appear to be saying something remarkable


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