All logic texts are divided into two parts. In the first part, on deductible logic, the fallacies are explained; in the second part, on inductive logic, they are committed.

The business of the philosopher is well done if he succeeds in raising genuine doubt.

Wisdom is not to be obtained from textbooks, but must be coined out of human experience in the flame of life.

If a philosophic theory is once ruled out of court, no one can tell when it will appear again.

Conservatism clings to what has been established, fearing that, once we begin to question the beliefs that we have inherited, all the values of life will be destroyed.

By no amount of reasoning can we altogether eliminate all contingency from our world. Moreover, pure speculation alone will not enable us to get a determinate picture of the existing world. We must eliminate some of the conflicting possibilities, and this can be brought about only by experiment and observation.

Liberalism regards life as an adventure in which we must take risks in new situation, in which there is no guarantee that the new will always be the good or the true, in which progress is a precarious achievement rather than inevitability.