The end of science is not to prove a theory, but to improve mankind.

It is only a step from boredom to disillusionment, which leads naturally to self-pity, which in turn ends in chaos.

Moderation is the secret of survival.

A man without ethics is a wild beast loosed upon this world.

I am using the word theory as a scientist means it: a set of ideas so well established by observations and physical models that it is essentially indistinguishable from fact. That is different from the colloquial use that means "guess." To a scientist, you can bet your life on a theory. Remember, gravity is "just a theory" too.

In science, there has never been a more well-founded theory than evolutionary theory. It's as good as science gets.