Resting on your laurels is as dangerous as resting when you are walking in the snow. You doze off and die in your sleep.

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

If you tried to doubt everything you would not get as far as doubting anything. The game of doubting itself presupposes certainty.

In order to be able to set a limit to thought, we should have to find both sides of the limit thinkable (i.e. we should have to be able to think what cannot be thought).

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.

A French politician once wrote that it was a peculiarity of the French language that in it words occur in the order in which one thinks them.

Just be indipendent of the external world, so you don't have to fear for what's in it.