A sane mind should not be guilty of a logical fallacy, yet there are very fine minds incapable of following mathematical demonstrations.

Point set topology is a disease from which the human race will soon recover.

It is by logic that we prove, but by intuition that we discover. To know how to criticize is good, to know how to create is better.

There are no solved problems; there are only problems that are more or less solved.

The scientist does not study nature because it is useful; he studies it because he delights in it, and he delights in it because it is beautiful.

Doubt everything or believe everything: these are two equally convenient strategies. With either we dispense with the need for reflection.

If nature were not beautiful, it would not be worth knowing, and if nature were not worth knowing, life would not be worth living

It is through science that we prove, but through intuition that we discover.

Geometry is the art of correct reasoning from incorrectly drawn figures.

One geometry cannot be more true than another; it can only be more convenient.

It is far better to foresee even without certainty than not to foresee at all.

The Light shines brightest, when the world is at its darkest.

The eye of your mind—your intelligence

During the war some of the country’s sharpest minds had looked as if they had been dragged through a hedge backwards.

...the weather was atrocious. A frightful storm burst upon us. We camped literally in water...To cap our woe, there was no means to light a single fire. We had to imagine dinner.

Arne Duncan is done more to bring our educational system, sometimes kicking and screaming, into the 21st century than anyone else.

It wasn't my choice to be an open book, but when people found out what my life was like when I was 14 or 15, I didn't deny it. I think the more imperfect you are, the more human you are.

If a lie is only printed often enough, it becomes a quasi-truth, and if such a truth is repeated often enough, it becomes an article of belief, a dogma, and men will die for it.

Anything that is non-violent is OK with me.

It's easy. You draw a red line on the ground, right? Then you wait for a chicken to come along. When he arrives, he puts his beak right on the line and he's hypnotized!

I have no idea what the next project will be and if there's a next project. I don't even know if we're all going to be here tomorrow, but I'm pretty optimistic.