And I shall always hold myself more obliged to those by whose favour I enjoy uninterrupted leisure than to any who might offer me the most honourable positions in the world.

It's the familiar love-hate syndrome of seduction: "I don't really care what it is I say, I care only that you like it."

The nature of matter, or body considered in general, consists not in its being something which is hard or heavy or coloured, or which affects the senses in any way, but simply in its being something which is extended in length, breadth and depth.

To live without philosophizing is in truth the same as keeping the eyes closed without attempting to open them.

I have concluded the evident existence of God, and that my existence depends entirely on God in all the moments of my life, that I do not think that the human spirit may know anything with greater evidence and certitude.

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

If you would be a real seeker after truth, it is necessary that at least once in your life you doubt, as far as possible, all things.