Pragmatism is worth studying from a pragmatic perspective. Materialism is worth studying from a materialist perspective. But postmodernism is not worth studying from a postmodernist perspective, so be careful to choose the right philosophies to begin with. Bwa ha ha.

Seriously though, the Less Wrong sequences are great. Eliezer started with math (Bayesianism) and science (cognitive science) and went ahead and pwned a huge swath of philosophy by staying within the well-established mathematical and cognitive frameworks. Philosophical subjects like 'aesthetics' are still difficult. (Schmidhuber's work on it is interesting though, and he approaches it from a super-simplified computer science perspective.) But old dilemmas like 'free will' and 'moral realism vs. antirealism' are dissolved.