Plato, despite his intellect (or perhaps because of it), turned out to be, as you say yourself, "naive and mistaken".

Yet Diogenes was able to see that about Plato then, as a contemporary.

And while it's true that he never sat down to write anything himself, his work has endured via written accounts of others (Diogenes was a real person, not a mythical figure).

Every reddit commenter is "able to see" that my essays are mistaken. Does that make them smart?

"Dear Ladies and Gentlemen, I am here today to convince you that the Great Gatsby could not possibly be an allegory for animal beastiality. I have three reasons for this belief. First, none of the main characters in Gatsby are animals. While Daisy does have a pet dog, there is no reason to believe that Gatsby ever expresses an interest in man-on-dog relations. [insert paragraphs two and three.] In conclusion, the Great Gatsby could not possibly be an allegory for animal beastiality, and it would be simply absurd to believe otherwise."

/Agreeing with pg, intelligence can only be demonstrated by finding what is, not what isn't.

I don't know what motivates people on reddit (don't they all upvote you automatically, like the people here?), but Diogenes' criticism of Plato was not simple whining, it was criticism based on a serious philosophy (cynicism) which stands in stark contrast to Plato's.

what does "smart" mean?

For a better presentation of the contemporary view of philosophers like Plato, you should read Aristophane's Clouds. It's also alot deeper in meaning than a mere facile mockery of poorly understood ideas.

It's been a while since I read the Clouds. IIRC, it was a lot of scatological and Mae West style humor (i.e. "Is that a sword under your tunic, or are you happy to see me?").

Aristophanes has literary value, but he was just exposing holes in Plato's logic for comedic and theatrical value; he was not himself a serious philosopher.

... Serious Philosopher.

Isn't that the whole problem expressed in two words?

Euclid was arguably "more serious" as a philosopher than a mathematician -- his principal contribution was to build a logical framework around others' results.

I want to start punning now -- who was more serious, Edward Teller or Richard Feynmann? -- but it's not useful. I'll simply note a certain dissonance in calling Diogenes serious, as you seem to.

Just remember how important the fool is in Shakespeare...

Leo Strauss would say otherwise. He has a whole book about Aristophane's take on Socrates, highlighting the crucial tension between the philosopher and the rest of society - the reason Socrates was killed. According to Allan Bloom, the whole enlightenment project can be explained as an attempt to solve this problem by displacing religion with philosophy, through science.

IMHO it's hard to argue that any philosopher is more influential than Plato, especially when you consider the clear neo-Platonic influences on Christian theology, and the subsequent influence that that tradition has had on Western civilization.

Influential, yes.

Plato was an elitist to the extreme, and his notions of a rigid class hierarchy did shape early feudal civilization in Europe.

But most important? Would you want to live in his Republic?

Even more important, was Socrate's Republic meant to be taken seriously?

Elaboration: keep in mind the whole point of creating a city in words was to get a look at the soul, and Socrates hints at the fact the city wouldn't be practical in real life.

Can you explain how the Republic influenced the Merovingians?

Not sure what you're referring to there, but the feudal ideas of class determined by birth and lack of social mobility were adopted from the Republic (though the ruling classes certainly took some liberties in their interpretation; some analyses of the Republic suggest it wasn't meant to be quite so rigid).

You're simply restating what you said before.

The germanic tribes already had class structure before they crossed over into the former imperial territories. And in any case, every settled agricultural society in history (Egypt, India, China) has had so far as we know a rigid social hierarchy. That of medieval Europe was by world standards comparatively porous. So unless you can point to some specific evidence that the germanic tribes that ruled early medieval Europe were influenced by the Republic, we should assume that they were just doing what they would have done anyway.

FWIW, I do remember a reference to early Catholic structure based on the Republic, but it'll take me a while to go back and find that reference.

We've gone off-topic, though: the main point here is that Diogenes' own philosophy is worthy, even though society at that time found it less palatable than Plato's.

People ignored it (and still do) because it's less certain than Plato's "reliable" model of patterns, and also because it means giving up material comforts.