When you come to look into this argument from design, it is a most astonishing thing that people can believe that this world, with all the things that are in it, with all its defects, should be the best that omnipotence and omniscience has been able to produce in millions of years.

Inferences of Science and Common Sense differ from those of deductive logic and mathematics in a very important respect, namely, when the premises are true and the reasoning correct, the conclusion is only probable.

Never try to discourage thinking, for you are sure to succeed.

The wise use of leisure, it must be conceded, is a product of civilization and education.

There lies before us, if we choose, continual progress in happiness, knowledge and wisdom. Shall we instead choose death, because we cannot forget our quarrels? I appeal as a human being to human beings; remember your humanity, and forget the rest.

Morality in sexual relations, when it is free from superstition, consists essentially in respect for the other person, and unwillingness to use that person solely as a means of personal gratification, without regard to his or her desires.

When I was a child . . . Only virtue was prized, virtue at the expense of intellect, health, happiness, and every mundane good.