Absolute space, that is to say, the mark to which it would be necessary to refer the earth to know whether it really moves, has no objective existence.

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.

She could not bear to look at him just now. If she did, she might well slap him again. Or cry. Or kiss him. And never know which was right and which was wrong and which was madness.

Minimalism is the intentional promotion of the things we most value and the removal of anything that distracts us from it.

Part of the beauty of Silicon Valley is that people generally encourage you to think crazy. It's the hypothesis that there's nothing sacred that can't be changed.

SpaceX has the potential of saving the U.S. government $1 billion a year. We are opposed to creating an entrenched monopoly with no realistic means for anyone to compete.

I've learned to accept birth and death . . . but sometimes I still worry about what lies between.

The Laws of Reasoning consist of the ground, the path, and the result. ...Suffering is in the mind. How we perceive happiness determines our suffering or not.

Without challenges, the human body will soften. We thrive when we push our boundaries, reach goals, and blast personal records. We perform better, we look better, and we feel alive.

It is reported that about 30% of the world's population is unemployed. That's worse than the Great Depression, but it's now an international phenomenon.

Women with whiskers... its a bummer.

Self-mastery and self-discipline are the foundation of good relationships with others.