People tend to forget that ancient Greek philosophers were… well, ancient. It’s useful to read their works and some of them do still have ideas that can apply today. For example, the stoic approach of “you make your own misfortune” is relevant to mental health today to a certain degree. Or Thucidedes’ approach to chronicling the Peloponnesian war has a very materialist approach.

But ofcourse, they lived in an age where slavery was acceptable and the main form of government was a mixture of oligarchy and monarchy. The ancient Greek world was chronically afflicted by steady xenophobia and women were largely seen as property (with the possible exception of Sparta where women were likely the economical elite). And ofcourse most people didn’t tend to know a whole lot about the physical world around them. It’s only natural that the bulk of these thinkers were idealists and propping up the elite. Their ideas on politics, economics, and to a large extent, science are pretty much outdated. There’s no denying, however, that they set the stage for future advancements, including Marxism. Marx’s ideas were largely formed in his younger years, by thinking and refuting the idealism and elitism of the Ancient Greek world and its offspring in contemporary Western thinking.