The best time to plant a tree was 25 years ago. The second best time is today.

We are survival machines – robot vehicles blindly programmed to preserve the selfish molecules known as genes.

Science is about understanding the world, and engineering is about changing it.

The man who does not read has no advantage over the man who cannot read.

You don't need to be perfect to inspire others. Let people get inspired by how you deal with your imperfections.

The test of a first-rate intelligence is the ability to hold two opposed ideas in the mind at the same time, and still retain the ability to function.