'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.

An image is not a picture, but a picture can correspond to it.

The world is the totality of facts, not of things

Think of the tools in a tool-box: there is a hammer, pliers, a saw, a screwdriver, a rule, a glue-pot, nails and screws.--The function of words are as diverse as the functions of these objects.

It is one of the chief skills of the philosopher not to occupy himself with questions which do not concern him.

Logic must look after itself. In a certain sense, we cannot make mistakes in logic.

Our civilization is characterized by the word "progress." Progress is its form rather than making progress being one of its features. Typically it constructs. It is occupied with building an ever more complicated structure. And even clarity is sought only.