Every sign by itself seems dead. What gives it life?--In use it is alive. Is life breathed into it there?--Or is the use its life?

What is your aim in philosophy? To show the fly the way out of the fly-bottle.

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.

If there were a verb meaning "to believe falsely," it would not have any significant first person, present indicative.

There can never be surprises in logic.

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.

Where two principles really do meet which cannot be reconciled with one another, then each man declares the other a fool and a heretic