I would go with Hume as well. Not only was he far ahead of his time, but it also seems as if virtually everyone who came after him demonstrated a significant backslide from the extremely high level of clarity he brought to the table on so many topics.
Also I should mention that it's my contention that despite being considered by virtually all accounts to be one of the greatest thinkers in history, it nevertheless seems to be the case that there are large parts of his work that most people haven't yet seen the significance of. He apparently once stated that justice will not be done to him in his lifetime. I'd go further and make the perhaps controversial point that justice still hasn't been done to him. I hope to work toward changing this at some point.
Disclaimer: No evidence given here. Just throwing my opinion out there.
This conversation has made me want to read Hume, thus – on that note, is there anything in particular you think I should pay attention to?
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?