DIOGENES
THE CYNIC
Method
Diogenes loved to shock, not only through his behaviour but also through argument. By using argument in classic logical style to justify outrageous behaviour, he ridiculed the all too clever nature of sophistical arguments. There is no impropriety in stealing from a temple, he argued, because: "All things belong to the gods. The wise are friends of the gods, and friends hold things in common. Therefore all things belong to the wise." Since all elements are contained in all things, there is nothing to prevent eating the flesh of any animal, including human flesh.
Philosophical debate took on a new meaning when Diogenes was one of the protagonists. His response to Plato's definition of man as "an animal, biped and featherless" was to pluck a fowl and and bring it into a lecture room, proclaiming: "This is Plato's man." Plato was forced to add "having broad nails" to his definition. Diogenes utterly rejected Platonic idealism, which Plato attributed to Diogenes' stupidity. Both accused each other of arrogance, with Plato claiming that Diogenes was overly proud of his lack of pride.
(Diogenes Laertes VI.37)