It is only theory that makes men completely incautious.

Theory helps us to bear our ignorance of facts.

It is better to emit a scream in the shape of a theory than to be entirely insensible to the jars and incongruities of life and take everything as it comes in a forlorn stupidity.

Let us work without theorizing ... 'tis the only way to make life endurable.

The utmost abstractions are the true weapons with which to control our thought of concrete fact.

The first time I came to the Comedy Festival some nutcase shot a bunch of people in Tasmania. I thought, 'Oh, that's just Tasmania.' The second time I came, some nut shot up Columbine High School. Now I'm here again, and another nut just shot up a high school in Minnesota. If you can't see the connection between me playing the Comedy Festival and mass murder, you're no good at conspiracy theories.

Ten geographers who think the world is flat will tend to reinforce each other's errors ... Only a sailor can set them straight.

No matter what occurs, there's always someone who believes it happened according to his pet theory.

Generally, the theories we believe we call facts and the facts we disbelieve we call theories.

Never worry about theory as long as the machinery does what it's supposed to do.