In terms of what counts as "philosophy", I was using a fairly modern conception of it. If that is granted (although come to think of it I could be challenged on that), then it follows that modern scientists have generally not considered such questions- Einstein, Darwin etc have not considered questions that fit into the modern idea of philosophy.
I also see no reasonable way to argue that there is "no fact of the matter" about whether morality is true or not. The basic idea of "just plain right/wrong" is incoherent and therefore clearly wrong in the same sense free will is clearly wrong.
What counts as philosophy: my point wasn't that science should be included under the heading of "philosophy", but that scientific advances may have had a big impact on philosophical questions.
Morality: I think I wasn't clear enough. (Either that or I'm now misunderstanding you.) I wasn't saying there might be no fact of the matter about whether moral realism is correct; I was saying that if moral realism is incorrect, there might be no fact of the matter about any question of the form "is doing X in situation Y morally right or not?". (...
Since LessWrong is a major congregation point for certain philosophical ideas, and because people here tend to be more objective (in the sense of not being self-deluded) than elsewhere, I thought I'd ask people's views.
To be clear, by "Greatest Philosopher" I am referring not to the most correct philosopher in human history but the one who deserves the most credit for advancing human philosophy towards being more true.
Off the top of my head I would say that a prime candidate would be Hume- amongst other things he rejected the idea of a soul, realised to a much greater extent than his predecessors the limits of human knowledge, and opposed the idea that reason is somehow an objective force that can make priorities independent of emotions.
Aristotle deserves considerable credit relative for his time but doesn't make the list because although it wasn't his fault his ideas were dogmatically accepted and held back both science and philosophy later on.
Your thoughts?