Because he was amazing. Wonderful writer, deep and original philosophical positions, tantalizing arguments. (Read his Enquiries , for instance.) Also, by all counts, a remarkable person. (Read Mossner's biography.)

I was also very moved reading La Nausée , but it didn't ignite anenduring interest in Sartre's philosophy so I'm unable to say whatconnection he thought there was between Roquentin's experience and his views in, say, Being and Nothingness . In general, I think the question of the relation between one's psychological make-up and one's philosophical outlook, interests, and style is an interesting one. You can read more about Sartre and existentialism in two entries from the Stanford Encyclopedia of Philosophy .

In On the Genealogy of Morals, Friedrich Nietzsche says that "A married philosopher belongs to comedy" (with the exception of "the mischievous Socrates").

Can we really defend Socrates here though? (Note: It's early Saturday morning and this is relevant to present fearless wading into rough waters.) He says that he is "likely to be wiser" by virtue of not asserting that he knows something worthwhile. But isn't wisdom knowledge? Doesn't being wiser require knowing a little more? If so, then it seems that Socrates really is saying that he knows that he doesn't know anything worthwhile. (That's the knowledge that makes him just a tad wiser.) And now we're back to worrying whether Socrates' assertion is paradoxical. I can imagine two responses: (A) one might claim that one's failure to know anything worthwhile isn't itself a worthwhile thing to know (and so Socrates' claim to knowledge doesn't clash with what he claims to know, viz. that he knows nothing worthwhile). Or (B) one might hold that one could be wiser simply by failing to claim knowledge that one doesn't have (so we can make sense of Socrates' claim to being slightly...

Again, this awaits a Descartes scholar, but what Descartes says in his "First Meditation" is this: Andbesides, as I sometimes imagine that others deceive themselves in thethings which they think they know best, how do I know that I am notdeceived every time that I add two and three, or count the sides of asquare, or judge of things yet simpler, if anything simpler can beimagined? So it seems Descartes argues that, as far as we can tell by the end of the "First Meditation",we could be wrong about (and so can't be said to know) basiccomputational facts, wrong about (what philosophers often call) analytictruths (like "A square has four sides"), and even wrong about "yet simpler"matters (like logical laws, perhaps).

I think you're right that there is something inconsistent about theclaim that "X [some other claim held true] is the only truth". Thankfully, that's not what Descartesheld. He tried to show how all our knowledge (and he thought that weknew many truths) could ultimately be based on certain rock-solidstarting points. One of these was that I (understood asmy present thinking self) exist. This claim is not something that couldbe intelligibly doubted, he argued, because the very act of doubting itshows that it's correct. On the basis of this slimfoundation, Descartes attempted to erect the entire edifice of ourknowledge. For a modernized translation of Descartes' great Meditations on First Philosophy , see here .

You can find a modernized "translation" of Berkeley's Principles of Human Knowledge here .