A tautology's truth is certain, a proposition's possible, a contradiction's impossible.

At the core of all well-founded belief lies belief that is unfounded.

A main cause of philosophical disease-an unbalanced diet: one nourishes one's thinking with only one kind of example.

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.

All I know is what I have words for.

That the world is, is the mystical.

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