Of the word ΕΙ engraven over the gate of Apollo's temple at Delphi (21)

Now, as for those who think Apollo and the Sun to be the same, they are to be caressed and loved for their ingenuity, as placing the notion of God in that which they most reverence, of all things that they know and desire. And now, as if they were dreaming of God the most glorious dream, let us stir up and exhort them to ascend higher, and to contemplate his reality and his essence; but to honor also this his image (the Sun), and to venerate that generative faculty he has placed in it, since it exhibits in some sort by its brightness—as far as it is possible for a sensible thing to represent an intellectual, and a movable thing that which is permanent—certain manifestations and resemblances of his benignity and blessedness. But as for those his sallyings out and changes, when he casts forth fire, ⋯ and when he again draws himself in, afterwards extending himself into the earth, sea, winds, animals, and strange accidents both of animals and plants, they cannot so much as be hearkened to without impiety; or else God will be worse than the child in the poet,—who made himself sport with a heap of sand, first raised and then

again scattered abroad by himself,—if he shall do the same in respect of the universe, first framing the world when it was not, and then destroying it when made. On the contrary, whatsoever of him is in any sort infused into the world, that binds together its substance, and restrains the corporeal weakness which tends to corruption. And it seems to me that this word is chiefly opposed to that doctrine, and that Εἶ, Thou art, is spoken to this God, as testifying that there is never in him any going forth or change. But to do and suffer this agrees to one of the other Gods, or rather Daemons, ordained to take care about Nature in generation and corruption; as is immediately manifest from their names, being wholly contrary and of different significations. For the one is called Apollo (or not many), the other Pluto (or many); the one Delius (from clearness), the other Aidoneus (from obscurity); the one Phoebus (or shining), the other Scotius (or dark); with the one are the Muses and Mnemosyne (or song and memory) with the other Lethe and Siope (or forgetfulness and silence). The one is (from contemplating and showing) named Theorius and Phanaeus; the other is

Prince of dark night and sluggish sleep, whose fate

Is that men him most of all Gods do hate.

Of Apollo also Pindar not unpleasantly sung, that he

The gentlest of all Gods to mortals is declared.

And therefore Euripides rightly also said:

These mournful songs suit well with men deceased,

With which gold-haired Apollo’s no way pleased.

And before him Stesichorus:

Apollo joys in sports and pleasant tones;

But Pluto takes delight in griefs and moans.

Sophocles also evidently attributes to either of them his proper instruments, in these words:

Neither the lute nor psaltery is fit

For mournful matters.

For it is but very lately, and in a manner of yesterday, that the pipe has dared to introduce itself into delightful matters; having in former times drawn men to mourning, and possessing about these things no very honorable or splendid employment. But afterwards all was brought into confusion, which was due especially to those who confounded the affairs of the Gods with those of the Genii.

But the sentence, Know thyself, seems in one respect to contradict this word EI, and in another to agree with it. For the one is pronounced with admiration and veneration to God, as being eternal; and the other is a remembrance to mortal men of their nature and infirmity.