Thank you for those thoughts, dear Logicon!

There are a lot of problems to system-construction, as well as to the question what is to be conceived as a system and what not.

Plato wrote dialogues, and letters - not much more, except for some lecture notes that have disappeared apparently (says at least some of the histories of philosophy, I am not exactly sure how much disagreement there is here). So where's the system?

Systems, I think, were first constructed at the dawn of the modern age - perhaps mainly starting with Descartes and his search for the ultimate foundations.

And Schopenhauer - now THAT is a hard one. On the one hand, he was not an "academic" philosopher, nor was his thinking based on heavy technical terminology or heavy argumentation (unlike Kant's). On the other hand, Schopenhauer, in his own philosophy, was after something systematical (if we think about Die Welt als Wille und Vorstellung, mainly). He wanted to show what his corrected version of the Kantian line of thinking would be (we all know about his sentiments towards the other German idealists!). So again, he did replace a system with another.

It is really problematic, as we modern people tend to think in terms of "systems" and "schemes" what comes to ancient philosophy as well. We ought not to. We ought to see very many separate questions, and very many lines of thinking - which DO, I admit, especially in Plato, form a system-like, unified line of thought. (For example, explaining the problems with universal concepts and the problems with sentences that will never be eternally true, by conceiving of another world - of those concepts, eternally.)

Do you agree? :-)