It is said also that Antisthenes, being about to read publicly something that he had composed, invited Plato to be present. And on his inquiring what he was about to read, Antisthenes replied that it was something about the impossibility of contradiction. “How then,” said Plato, “can you write on this subject?” thus showing him that the argument refutes itself. Thereupon he wrote a dialogue against Plato and entitled it Sathon. After this they continued to be estranged from one another. They say that, on hearing Plato read the Lysis, Socrates exclaimed, “By Heracles, what a number of lies this young man is telling about me!” For he has included in the dialogue much that Socrates never said.
Source: Lives of the Eminent Philosophers (1925) by Diogenes Laërtius, translated by Robert Drew Hicks. A Loeb Classical Library edition; volume 1 published 1925; volume 2 published 1925. WikiSource.