The biggest problem I have with the idea that Plato is a fantasy is that according to the various histories, he taught Aristotle. So if Plato did not exist, we then have to extrapolate that Aristotle did not exist either. Yet the mode of thought of Western humanity is Aristotelian. read more
Concerning reality nobody can prove anything, nor even that there is a reality to start with. But we can evaluate the plausibility, and there are strong evidences that Plato existed, nor any evidence that he did not exist, or that he was an imaginary guy belonging to some fiction. read more
Cynics in general were not very popular in Plato´s academy, and gaining reputation and merit through philosophy is against the basic value of cynics. On the other hand, it is said that No-one could beat Diogenes of Sinope in argumentations. read more