Evolution is an organizing principle and when we call it a theory, we mean it's a theory, we don't mean that it's a belief that someone holds.

- Alan I. Leshner

There is no such thing as recreational drug use.

- Alan I. Leshner

Evolution is far more than a belief or an educated guess about how people came to be as they are. It is, in fact, the product of converging evidence …

- Alan I. Leshner