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.

After experience had taught me that all the usual surroundings of social life are vain and futile; seeing that none of the objects of my fears contained in themselves anything either good or bad, except in so far as the mind is affected by them, I finally resolved to inquire whether there might be some real good having power to communicate itself, which would affect the mind singly, to the exclusion of all else: whether, in fact, there might be anything of which the discovery and attainment would enable me to enjoy continuous, supreme, and unending happiness.

Only free men are thoroughly grateful one to another.

Nature is satisfied with little; and if she is, I am also.

God is the indwelling and not the transient cause of all things.

From what has been said we can clearly understand the nature of Love and Hate. Love is nothing else but pleasure accompanied by the idea of an external cause: Hate is nothing else but pain accompanied by the idea of an external cause. We further see, that he who loves necessarily endeavors to have, and to keep present to him, the object of his love; while he who hates endeavors to remove and destroy the object of his hatred.

Except God no substance can be granted or conceived. .. Everything, I say, is in God, and all things which are made, are made by the laws of the infinite nature of God, and necessarily follows from the necessity of his essence.