“Pleasure is never as pleasant as we expected it to be and pain is always more painful. The pain in the world always outweighs the pleasure. If you don't believe it, compare the respective feelings of two animals, one of which is eating the other.”

“Pleasures are always children, pains always have wrinkles.”

“As the thing more perfect is,
The more it feels of pleasure and of pain.”

“A person who feels pleasure in producing pain in someone else in a sexual relationship is also capable of enjoying as pleasure any pain which he may himself derive from sexual relations. A sadist is always at the same time a masochist.”

“There is no fundamental difference between man and animals in their ability to feel pleasure and pain, happiness, and misery.”

“Oh, are not the pleasures in life, in this daily round, trifling compared with the pains!”
Satin parva res est voluptatum in vita atque in aetate agunda praequam quod molestum est?

“The inextricable way pleasure and pain are mixed up with each other in this world is a mournful fact to beings who are all the time striving for pleasure alone. In the ideal world there is no pain, no misery. There is nothing but happiness. But in our world pain seems to have been the original feeling, the first one to appear in the evolution of sentiency. Pleasure is a sort of after-thought, a secondary attribute of consciousness which developed later as an aid to pain in keeping living beings straight. Pain is a whip, a penalty. Pleasure is a reward or bribe. Pain is a curse. We are all the time trying to minimize and escape it. In an ideal world the inhabitants never have any impulses that drive them to improper acts. All their impulses are good. Every act is proper and right. Ideal beings need only to live and act in order to be happy. We are not ideal beings. Our world happens to be one affording almost unlimited opportunities for improvement.”

“For pain is perhaps but a violent pleasure? Who could determine the point where pleasure becomes pain, where pain is still a pleasure? Is not the utmost brightness of the ideal world soothing to us, while the lightest shadows of the physical world annoy?”

“Pleasure has desire in it. Desire is pain. There is no satisfaction. So pleasure is pain.”

“The secret of success is learning how to use pain and pleasure instead of having pain and pleasure use you. If you do that, you're in control of your life. If you don't, life controls you.”