Useful Quotes

I have called this principle, by which each slight variation, if useful, is preserved, by the term of Natural Selection.

If then we have under nature variability and a powerful agent always ready to act and select, why should we doubt that variations in any way useful to beings, under their excessively complex relations of life, would be preserved, accumulated, and inherited?

The production of too many useful things results in too many useless people.

Books are as useful to a stupid person as a mirror is useful to a blind person.