The man of knowledge must be able not only to love his enemies but also to hate his friends.

Partial knowledge is more triumphant than complete knowledge; it takes things to be simpler than they are, and so makes its theory more popular and convincing.

The stomach is the only part of man which can be fully satisfied. The yearning of man's brain for new knowledge and experience and for more pleasant and comfortable surroundings never can be completely met. It is an appetite which cannot be appeased.

Every acquisition, every step forward in knowledge is the result of courage, of severity toward oneself, of cleanliness with respect to oneself.

Read 500 pages every day. That's how knowledge works. It builds up like compound interest.

Ignorance is the curse of God; knowledge is the wing wherewith we fly to heaven.