I arbitrarily looked up Ludwig Wittgenstein on a quotations site and here are a few of the great lines I found:
"Hell isn't other people. Hell is yourself."
"I don't know why we are here, but I'm pretty sure that it is not in order to enjoy ourselves."
"I am sitting with a philosopher in the garden; he says again and again 'I know that that's a tree' pointing to a tree that is near us. Someone else arrives and hears this, and I tell him : 'This fellow isn't insane. We are only doing philosophy.' "
"A serious and good philosophical work could be written consisting entirely of jokes."
"Never stay up on the barren heights of cleverness, but come down into the green valleys of silliness."
"The real question of life after death isn't whether or not it exists, but even if it does what problem this really solves."
I can understand where the gloomier great quotes come from, considering that for one thing 3 of his brothers committed suicide (that HAS to be a record!) and a 4th concert pianist brother had an arm blown off in World War One...but I was surprised by the lighter-hearted quotes, and I'm glad for him that he had them in him.
My favorite is probably the last quote, which seems to be very serious and very funny at the same time...In fact, I think I'll toss it out over at the "Religion" thread and see if the boys over there can get a chuckle or an outraged theory about it...