Faith in the possibility of science, generated antecedently to the development of modern scientific theory, is an unconscious derivative from medieval theology.

The merely well-informed man is the most useless bore on God's earth.

No science can be more secure than the unconscious metaphysics which tacitly it presupposes.

To be an abstraction does not mean that an entity is nothing. It merely means that its existence is only a factor of a more concrete element of nature.

The difference between ancients and moderns is that the ancients asked what have we experienced, and moderns asked what can we experience.

Each human being is a more complex structure than any social system to which he belongs.

Whenever a text-book is written of real educational worth, you may be quite certain that some reviewer will say that it will be difficult to teach from it. Of course it will be difficult to teach from it. It it were easy, the book ought to be burned.