In the full sense of the word this question is unanswerable. I don’t know a serious educated person who does not worry about it. On the one hand, if you do not read philosophers in the right order you are bound to miss the significance of something the later person says. I’m not saying you run the risk of missing that significance; you are guaranteed to do so. And yet this is a half-truth, because there is plenty you will miss if you start back at the beginning of philosophy and proceed to the end. First of all there’s the obvious problem of motivation that your question implies. If you have to read Descartes before Kant, and Aristotle before Descartes, and so on, you will have been lost or sidetracked before you ever reached the people like Nietzsche and Kierkegaard who first drew your attention. Demanding a strict chronological reading list is impractical. There’s another kind of problem that affects even industrious people who are incapable of being bored or sidetracked. In many cases we...

I can’t resist offering the follow-up to Miriam Solomon’s response, not because I’ll say what she would say, but precisely because I think I come at this question differently from her. So with any luck you’ll get a second perspective on the same fundamental thought. Your professors were right to insist on the clear articulation of ideas and on the careful argumentation that takes us from premises to conclusions. Clarity and validity are two of the most important tools that philosophers work with. Some philosophers will agree with me that other tools or techniques are essential as well, such as the method of philosophical interpretation; but calling for more attention to philosophical interpretation does not have to mean neglecting argumentation. But even if we stick to clear terms and valid arguments, there are going to be more fundamental questions that guide us. What terms are worth clarifying? The important ones, of course. What subjects do we make arguments about? Again, the important...

Any responsible answer to this question has to be highly qualified and surrounded by admissions of ignorance. I’ll try not to get bogged down by describing what we don’t know, but you should realize how inconclusive any answer to your excellent question has to be. I don’t know enough about non-Western philosophers to tackle that part of the question. Let me say a few words about Thales, Anaximander, Pythagoras, and the rest. Not too long ago the standard claim about them was that they turned thinking decisively away from mythical thinking. Where myths described a world before the world we occupy, an earlier time in which different causes made things happen, these philosophers confined themselves to the world we know and the natural processes at work in this world. So, if they were to describe the origin of the universe, that origin would have to follow causal laws akin to the laws in effect today. This is our own scientific understanding of the universe today, incidentally. Whatever brought...