The human species took a crucial step forward when its vocal musculature came under operant control in the production of speech sounds. Indeed, it is possible that all the distinctive achievements of the species can be traced to that one genetic change.

The juvenile delinquent does not feel his disturbed personality. The intelligent man does not feel his intelligence or the introvert his introversion.

Better contraceptives will control population only if people will use them. A nuclear holocaust can be prevented only if the conditions under which nations make war can be changed. The environment will continue to deteriorate until pollution practices are abandoned. We need to make vast changes in human behavior.

Many social practices essential to the welfare of the species involve the control of one person by another, and no one can suppress them who has any concern for human achievements

Science, not religion, has taught me my most useful values, among them intellectual honesty. It is better to go without answers than to accept those that merely resolve puzzlement.

Behavior is determined by its consequences.

A first principle not formally recognized by scientific methodologists: when you run into something interesting, drop everything else and study it.