Ludwig Wittgenstein

Ludwig Josef Johann Wittgenstein (26 April 1889 – 29 April 1951) Austrian philosopher who worked primarily in logic, the philosophy of mathematics, the philosophy of mind, and the philosophy of language. He is considered by some to be the greatest philosopher of the 20th century.

When we can't think for ourselves, we can always quote.
How small a thought it takes to fill a life.
Never stay up on the barren heights of cleverness, but come down into the green valleys of silliness.
Not how the world is, but that it is, is the mystery.
We are asleep. Our Life is a dream. But we wake up sometimes, just enough to know that we are dreaming.
Don't for heaven's sake, be afraid of talking nonsense! But you must pay attention to your nonsense.
If we take eternity to mean not infinite temporal duration but timelessness, then eternal life belongs to those who live in the present.
Only describe, don't explain.
If people never did silly things nothing intelligent would ever get done.
I am my world.
The real question of life after death isn't whether or not it exists, but even if it does what problem this really solves.
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.
The limits of my language means the limits of my world.
A serious and good philosophical work could be written consisting entirely of jokes.