The basis for poetry and scientific discovery is the ability to comprehend the unlike in the like and the like in the unlike.

Dissent is the mark of freedom, as originality is the mark of independence of mind. … No one can be a scientist … if he does not have independence of observation and of thought.

Beyond all our actions stands the larger shadow: How are we to choose between what we have been taught to think right and something else which manifestly succeeds?

The symbol and the metaphor are as necessary to science as to poetry.

The most powerful drive in the ascent of man is his pleasure in his own skill. He loves to do what he does well. And having done it well, he loves to do it better.

Every animal leaves traces of what it was; man alone leaves traces of what he created.

Satire is not a social dynamite. But it is a social indicator: it shows that new men are knocking at the door.