common sense is a very tricky instrument; it is as deceptive as it is indispensable.

If we would have new knowledge, we must get a whole world of new questions.

Common-sense knowledge is prompt, categorical, and inexact.

The faith of scientists in the power and truth of mathematics is so implicit that their work has gradually become less and less observation, and more and more calculation.... But the facts which are accepted by virtue of these tests are not actually observed at all.

What is artistically good is whatever articulates and presents feeling to our understanding.

A mind that is very selective to forms... is apt to use its images metaphorically, to exploit their possible significance for the conception of remote or intangible ideas.

To trace the development of mind from earliest times ... requires ... not a categorical concept, but a functional one.... The most promising operational principle for this purpose is the principle of individuation.