Cruel persecutions and intolerance are not accidents, but grow out of the very essence of religion, namely, its absolute claims.

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.

It has generally been assumed that of two opposing systems of philosophy, e.g., realism and idealism, one only can be true and one must be false; and so philosophers have been hopelessly divided on the question, which is the true one.

Liberalism is an attitude rather than a set of dogmas - an attitude that insists upon questioning all plausible and self-evident propositions, seeking not to reject them but to find out what evidence there is to support them rather than their possible alternatives.

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.

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