right now, i'm teaching both the analects of confucius and the republic of plato, as i often do. i think it's worth saying that both of these texts, and the 'golden ages' of human thought in which they emerged, were characterized by extremely fragmented prolitical situations, situations of wars and struggles between small states in close proximity and quick transition. without having done any very elaborate research to try to back this up, i'm going to say it's my impression that periods like that are characterized by creativity and innovation, whereas periods of well-consolidated large nations or empires have the opposite effect. another case: renaissance italy. really, even to try to understand the political landscape of 15th and 16th century on the italian peninsula is crazy. well you get machiavelli and humanism, michelangelo and leonardo and raphael, etc etc.
the roman period in philosophy is often undervalued for its interest and even its originality, but there is no denying that in many ways they were basically ramifying greek ideas and arts. or once china consolidated into an empire, there was far less creative thought, etc. in some ways the reasons are obvious; i do think that both the greeks and the chinese of the spring and autumn and warring states periods had to grapple with different social/political/aesthetic arrangements in close proximity. and if you don't, i don't think you start asking questions like, what is the best political system? also these big nations think they should be running the arts and philosophies, and characteristically take direct measures to establish an official ideology and crush outliers.
so, i'd say, if you want to make, profess, think, create, etc, you should pursue decentralization of political power everywhere all the time. or try this: the state is a force inimical to human thought and art. the more thorough state power, the less thinking and creating takes place. i say i could show that historically. that would be an argument for anarchism, y'all. and if you are casually contemplating a worldstate as our inevitable future, just let it occur to you that that's sort of the end of philosophy and art.