The highest endeavor of the mind, and the highest virtue, it to understand things by intuition.

I do not presume that I have found the best philosophy, I know that I understand the true philosophy.

The multitude always strains after rarities and exceptions, and thinks little of the gifts of nature; so that, when prophecy is talked of, ordinary knowledge is not supposed to be included. Nevertheless it has as much right as any other to be called Divine.

Pride is pleasure arising from a man's thinking too highly of himself.

Sadness diminishes a man's powers

Only free men are thoroughly grateful one to another.

I should attempt to treat human vice and folly geometrically... the passions of hatred, anger, envy, and so on, considered in themselves, follow from the necessity and efficacy of nature... I shall, therefore, treat the nature and strength of the emotion in exactly the same manner, as though I were concerned with lines, planes, and solids.