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 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 ugly to others, and that which appears to each man is the measure
The happy man . . . will be always or at least most often employed in doing and contemplating the things that are in conformity with virtue. And he will bear changes of fortunes most nobly, and with perfect propriety in every way.
There are, then, these three means of effecting persuasion. The man who is to be in command of them must, it is clear, be able (1) to reason logically, (2) to understand human character and goodness in their various forms, and (3) to understand the emotions--that is, to name them and describe them, to know their causes and the way in which they are excited.
We ought to be able to persuade on opposite sides of a question; as also we ought in the case of arguing by syllogism: not that we should practice both, for it is not right to persuade to what is bad; but in order that the bearing of the case may not escape us, and that when another makes an unfair use of these reasonings, we may be able to solve them.
We do not act rightly because we have virtue or excellence. But they hesitate, waiting for the other fellow to make the first move-and he, in turn, waits for you.
For even they who compose treatises of medicine or natural philosophy in verse are denominated Poets: yet Homer and Empedocles have nothing in common except their metre; the former, therefore, justly merits the name of the Poet; while the other should rather be called a Physiologist than a Poet.
It has been handed down in mythical form from earliest times to posterity, that there are gods, and that the divine (Deity) compasses all nature. All beside this has been added, after the mythical style, for the purpose of persuading the multitude, and for the interests of the laws, and the advantage of the state.