Don't think, but look! (PI 66)

Philosophy aims at the logical clarification of thoughts. Philosophy is not a body of doctrine but an activity. A philosophical work consists essentially of elucidations.

There are, indeed, things that cannot be put into words. They make themselves manifest. They are what is mystical.

'Imagine a person whose memory could not retain what the word 'pain' meant-so that he constantly called different things by that name-but nevertheless used the word in a way fitting in with the usual symptoms and presuppositions of pain'-in short he uses it as we all do. Here I should like to say: a wheel that can be turned though nothing else moves with it, is not part of the mechanism.

A propositional sign, applied and thought out, is a thought. A thought is a proposition with a sense.

Black seems to make a colour cloudy, but darkness doesn't. A ruby could thus keep getting darker without ever becoming cloudy; but if it became blackish red, it would become cloudy.

Philosophical problems arise when language goes on holiday