substitution of terms

“We cannot know of the gods whether they exist or do not exist, or of what sort they are. Much prevents: the obscurity of the subject and the brevity of human life.”

Protagoras, “On Gods,” in Diels-Krantz, Die Vorsokratiker (Berlin, 1951)
[Die Fragmente der Vorsokratiker (Berlin, 1903, 6th ed., rev. by Walther Kranz (Berlin: Weidmann, 1952; the editions after the 6th are mainly reprints with little or no change.)]

We cannot know of poems, what they mean or do not mean, or of what sort they are. Much prevents: the obscurity of the subject and the brevity of human life.

putting poets aside

And so a gathering like this of ours, when it includes such men as most of us claim to be, requires no extraneous voices, not even of the poets, whom one cannot question on the sense of what they say; when they are adduced in discussion we are generally told by some that the poet thought so and so, and by others, something different, and they go on arguing about a matter which they are powerless to determine. No, this sort of meeting is avoided by men of culture, who prefer to converse directly with each other, and to use their own way of speech in putting one another by turns to the test. It is this sort of person that I think you and I ought rather to imitate; putting the poets aside, let us hold our discussion together in our own persons, making trial of the truth and of ourselves.

—Socrates in Plato’s Protagoras (Leob classical edition, W.R.M. Lamb translation)