In the philosophic sense, observation shows and experiment teaches.

It is what we know already that often prevents us from learning.

The experimenter who does not know what he is looking for will not understand what he finds.

When we meet a fact which contradicts a prevailing theory, we must accept the fact and abandon the theory, even when the theory is supported by great names and generally accepted.

Man can learn nothing unless he proceeds from the known to the unknown.

The terrain is everything; the germ is nothing.

Art is 'I'; science is 'we'.

A fact in itself is nothing. It is valuable only for the idea attached to it, or for the proof which it furnishes.

Those who do not know the torment of the unknown cannot have the joy of discovery.

Science increases our power in proportion as it lowers our pride.

All the vital mechanisms, varied as they are, have only one object, that of preserving constant the conditions of life in the internal environment.

The true essence of greatness is in finding self in selfishness

Freedom is a gift that can never adequately be repaid.

It's true, some wine improves with age. But only if the grapes were good in the first place.

I was thinking, there are 5 million people, and I am just one of those 5 million. In the build-up to the war you see children playing in the street, and you think, ah, I'm going to be okay.

I love you just the way you are but you don't see you like I do. You shouldn't try so hard to be perfect. Trust me, perfect should try to be you.

We ought to fear a man who hates himself, for we are at risk of becoming victims of his anger and revenge. Let us then try to lure him into self-love.

When Satan's not in the mood, virtue triumphs. Hasn't even Satan a right not to be in the mood once in a while?

A heap of bricks is not yet a house.

If you elect me president, we will have a president that believes America is the greatest country in the world and we will have a president that acts like it.

Everyone is in love with the impossible; the impossible gives you neverending dreams and neverending hopes.