"Dicæarchus in his book of Antiquities, describing Greece, relates that under Saturn, that is in the Golden Age, when the ground brought forth all things abundantly, no one ate flesh, but every one lived on field produce and fruits which the earth bore of itself. ... Xenocrates the philosopher writes that at Athens out of all the laws of Triptolemus only three precepts remain in the temple of Ceres: respect to parents, reverence for the gods, and abstinence from flesh. Orpheus in his song utterly denounces the eating of flesh. I might speak of the frugality of Pythagoras, Socrates, and Antisthenes to our confusion: but it would be tedious, and would require a work to itself."
January 1, 1970
https://en.wikiquote.org/wiki/Vegetarianism