system
Given the following post, respond as if you're commenting on Reddit:
human
Was Plato BSing us when he suggested he had a separate, hidden philosophical system which he never covered in his writings?

According to Plato's letters (which I realize have prominent scholars arguing for and against in terms of authenticity) he denies that he has never written, or will ever write, a book on what he "seriously" studies. And as "Whenever one sees a man's written compositions-whether they be laws of a legislator or anything else in any other form-these are not his most serious works, if so be that the writer himself is serious." 

According to the seventh letter, the truth about "the highest things of nature" does not at all "admit of verbal expression like other studies". Avoidance of writing is "the greatest safeguard"; it is not right to divulge the truth improperly, the second letter states.

So this leads you to think that he never wrote about his true philosophical system. But I have a hard time believing that.  

This is because Plato's associates — Aristotle, Xenocrates, Crantor — base their interpretation of Plato's philosophy on statements made in the dialogues. 

How could people so close to him be unaware that his writings contained no serious teachings?
gpt
I think what Plato meant by that was that he understood correctly, that there was a deeper meaning and higher truth to reality than is apparent at once, an existential plane which transcends words and the physical realm and any attempts to describe in writing this meta-reality was at best a fruitless attempt and at worst an irresponsible and mistaken approach to the matter. Think of it as his own greek version similar to the philosophical system in Buddhism about the Two Truths doctrine in which there is a conventional truth and a higher ultimate truth. 

Then again, you can't blame him for saying that. 2500 years later, Wittgenstein arrived at the same conclusion. That the word is not the thing and that our model of reality is not reality itself.

It goes to show the timelessness of Plato's mind. A true genius for the ages.