Sokr. — It thus appears that you pursue pleasure as good, and avoid pain as evil. Pleasure is what you think good: pain is what you think evil: for even pleasure itself appears to you evil, when it either deprives you of pleasures greater than itself, or entails upon you pains outweighing itself. Is there any other reason, or any other ulterior end, to which you look when you pronounce pleasure to be evil? If there be any other between reason, or any other end, tell us what it is.[109] Prot. — There is none whatever. Sokr. — The case is similar about pains: you call pain good, when it preserves you from greater pains, or procures for you a future balance of pleasure. If there be any other end to which you look when you call pain good, tell us what it is. Prot. — You speak truly. Sokr. — If I am asked why I insist so much on the topic now before us, I shall reply, that it is no easy matter to explain what is meant by being overcome by pleasure; and that the whole proof hinges upon this point — whether there is any other good than pleasure, or any other evil than pain; and whether it be not sufficient, that we should go through life pleasurably and without pains.[110] If this be sufficient, and if no other good or evil can be pointed out, which does not end in pleasures and pains, mark the consequences. Good and evil being identical with pleasurable and painful, it is ridiculous to say that a man does evil voluntarily, knowing it to be evil, under the overpowering influence of pleasure: that is, under the overpowering influence of good.[111] How can it be wrong, that a man should yield to the influence of good? It never can be wrong, except in this case — when the good obtained is of smaller amount than the consequent good forfeited or the consequent evil entailed. What other exchangeable value can there be between pleasures and pains, except in the ratio of quantity — greater or less, more or fewer?[112] If an objector tells me that there is a material difference between pleasures and pains of the moment, and pleasures and pains postponed to a future time, I ask him in reply, Is there any other difference, except in pleasure and pain? An intelligent man ought to put them both in the scale, the pleasures and the pains, the present and the future, so as to determine the balance. Weighing pleasures against pleasures, he ought to prefer the more and the greater: weighing pains against pains, the fewer and the less. If pleasures against pains, then when the latter outweigh the former, reckoning distant as well as near, he ought to abstain from the act: when the pleasures outweigh, he ought to do it. Prot. — The objectors could have nothing to say against this.[113]
[109] Plato, Protag, p. 354 D. ἐπεὶ εἰ κατ’ ἄλλο τι αὐτὸ τὸ χαίρειν κακὸν καλεῖτε καὶ εἰς ἄλλο τι τέλος ἀποβλέψαντες, ἔχοιτε ἂν καὶ ἡμῖν εἰπεῖν· ἀλλ’ οὐχ ἕξετε. Οὐδ’ ἐμοὶ δοκοῦσιν, ἔφη ὁ Πρωταγόρας.
[110] Plato, Protag. p. 354 E. ἔπειτα ἐν τούτῳ εἰσὶ πᾶσαι αἱ ἀποδείξεις· ἀλλ’ ἔτι καὶ νῦν ἀναθέσθαι ἔξεστιν, εἰ πῃ ἔχετε ἄλλο τι φάναι εἶναι τὸ ἀγαθὸν ἢ τὴν ἡδονήν, ἢ τὸ κακὸν ἄλλο τι ἢ τὴν ἀνίαν, ἢ ἀρκεῖ ὑμῖν τὸ ἡδέως καταβιῶναι τὸν βίον ἄνευ λυπῶν;
[111] Plato, Protag. p. 355 C.
[112] Plato, Protag. p. 356 A. καὶ τίς ἄλλη ἀξία ἡδονῇ πρὸς λύπων ἐστὶν ἀλλ’ ἢ ὑπερβολὴ ἀλλήλων καὶ ἔλλειψις; ταῦτα δ’ ἐστὶ μείζω τε καὶ σμικρότερα γιγνόμενα ἀλλήλων, καὶ πλείω καὶ ἐλάττω, καὶ μᾶλλον καὶ ἧττον.
[113] Plato, Protag. p. 356 C.
Necessary resort to the measuring art for choosing pleasures rightly — all the security of our lives depend upon it.
Sokr. — Well then — I shall tell them farther — you know that the same magnitude, and the same voice, appears to you greater when near than when distant. Now, if all our well-doing depended upon our choosing the magnitudes really greater and avoiding those really less, where would the security of our life be found? In the art of mensuration, or in the apparent impression?[114] Would not the latter lead us astray, causing us to vacillate and judge badly in our choice between great and little, with frequent repentance afterwards? Would not the art of mensuration set aside these false appearances, and by revealing to us the truth, impart tranquillity to our minds and security to our lives? Would not the objectors themselves acknowledge that there was no other safety, except in the art of mensuration? Prot. — They would acknowledge it. Sokr. — Again, If the good conduct of our lives depended on the choice of odd and even, and in distinguishing rightly the greater from the less, whether far or near, would not our safety reside in knowledge, and in a certain knowledge of mensuration too, in Arithmetic? Prot. — They would concede to you that also. Sokr. — Well then, my friends, since the security of our lives has been found to depend on the right choice of pleasure and pain — between the more and fewer, greater and less, nearer and farther — does it not come to a simple estimate of excess, deficiency, and equality between them? in other words, to mensuration, art, or science?[115] What kind of art or science it is, we will enquire another time: for the purpose of our argument, enough has been done when we have shown that it is science.
[114] Plato, Protag. p. 356 D. εἰ οὖν ἐν τούτῳ ἡμῖν ἦν τὸ εὖ πράττειν, ἐν τῷ τὰ μὲν μεγάλα μήκη καὶ πράττειν καὶ λαμβάνειν, τὰ δὲ σμικρὰ καὶ φεύγειν καὶ μὴ πράττειν, τίς ἂν ἡμῖν σωτηρία ἐφάνη τοῦ βίου; ἆρα ἡ μετρητικὴ τέχνη, ἢ ἡ τοῦ φαινομένου δύναμις; … Ἆρ’ ἂν ὁμολογοῖεν οἱ ἄνθρωποι πρὸς ταῦτα ἡμᾶς τὴν μετρητικὴν σώζειν ἂν τέχνην, ἢ ἄλλην;
[115] Plato, Protag. p. 357 A-v. ἐπειδὴ δὲ ἡδονῆς τε καὶ λύπης ἐν ὀρθῇ τῇ αἱρέσει ἐφάνη ἡμῖν ἡ σωτηρία τοῦ βίου οὖσα, τοῦ τε πλέονος καὶ ἑλάττονος καὶ μείζονος καὶ σμικροτέρον καὶ ποῤῥωτέρω καὶ ἐγγυτέρω, ἆρα πρῶτον μὲν οὐ μετρητικὴ φαίνεται, ὑπερβολῆς τε καὶ ἐνδείας οὖσα καὶ ἰσότητος πρὸς ἀλλήλας σκέψις; Ἀλλ’ ἀνάγκη. Ἐπεὶ δὲ μετρητική, ἀνάγκῃ δήπου τέχνη καὶ ἐπιστήμη.