Gradually the conviction gained recognition that all knowledge about things is exclusively a working-over of the raw material furnished by the senses. ... Galileo and Hume first upheld this principle with full clarity and decisiveness.

You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat.

It takes a different kind of thinking to solve a problem than the kind of thinking which produced the problem.

Men marry women with the hope they will never change. Women marry men with the hope they will change. Invariably they are both disappointed.

The environment is everything that isn't me.

Strive not to be a success, but rather to be of value.

Understanding physics is child's play when compared to understanding child's play.