Diogenes Laërtius,
The Lives and Opinions of Eminent Philosophers
“ He was a great enemy of Arcesilaus. And once, seeing a bull of a monstrous conformation, having a womb, he said, “Alas! here is an argument for Arcesilaus against the evidence of his senses.” On another occasion, when a philosopher of the Academy said that he did not comprehend anything, he said to him, “Do not you even see the man who is sitting next to you?” ”
