Now it is established in the sciences that no knowledge is acquired save through the study of its causes and beginnings, if it has had causes and beginnings nor completed except by knowledge of its accidents and accompanying essentials.

Effective use of Braille is as important to the blind as independent mobility, knowledge in the use of adaptive technology, and the core belief that equality, opportunity and security are truly possible for all people who are blind.

Science consists exactly of those forms of knowledge that can be verified and duplicated by anybody.

Intuition does not in itself amount to knowledge, yet cannot be disregarded by philosophers and psychologists.

But the egoist has no ideals, for the knowledge that his ideals are only his ideals, frees him from their domination. He acts for his own interest, not for the interest of ideals.