Lust is to the other passions what the nervous fluid is to life; it supports them all, lends strength to them all ambition, cruelty, avarice, revenge, are all founded on lust.

Get it into your head once and for all, my simple and very fainthearted fellow, that what fools call humanness is nothing but a weakness born of fear and egoism; that this chimerical virtue, enslaving only weak men, is unknown to those whose character is formed by stoicism, courage, and philosophy.

Cruelty, very far from being a vice, is the first sentiment Nature injects in us all. The infant breaks his toy, bites his nurse's breast, strangles his canary long before he is able to reason; cruelty is stamped in animals, in whom, as I think I have said, Nature's laws are more emphatically to be read than in ourselves; cruelty exists amongst savages, so much nearer to Nature than civilized men are; absurd then to maintain cruelty is a consequence of depravity. . . . Cruelty is simply the energy in a man civilization has not yet altogether corrupted: therefore it is a virtue, not a vice.

Sexual pleasure is, I agree, a passion to which all others are subordinate but in which they all unite.

The pleasure of the senses is always regulated in accordance with the imagination. Man can aspire to felicity only by serving all the whims of his imagination.

Those laws, being forged for universal application, are in perpetual conflict with personal interest, just as personal interest is always in contradiction with the general interest. Good for society, our laws are very bad for the individuals whereof it is composed; for, if they one time protect the individual, they hinder, trouble, fetter him for three quarters of his life.

Conversation, like certain portions of the anatomy, always runs more smoothly when lubricated.