Rene descartes

Illusory joy is often worth more than genuine sorrow.

One cannot conceive anything so strange and so implausible that it has not already been said by one philosopher or another.

A state is better governed which has few laws, and those laws strictly observed.

Whenever anyone has offended me, I try to raise my soul so high that the offense cannot reach it.

The first precept was never to accept a thing as true until I knew it as such without a single doubt.

I am indeed amazed when I consider how weak my mind is and how prone to error.

The two operations of our understanding, intuition and deduction, on which alone we have said we must rely in the acquisition of knowledge.

Nothing is more fairly distributed than common sense: no one thinks he needs more of it than he already has.

Except our own thoughts, there is nothing absolutely in our power.

It is only prudent never to place complete confidence in that by which we have even once been deceived.