You can never know if a person forgives you when you wrong them. Therefore it is existentially important to you. It is a question you are intensely concerned with. Neither can you know whether a person loves you. It’s something you just have to believe or hope. But these things are more important to you than the fact that the sum of the angles in a triangle is 180 degrees. You don't think about the law of cause and effect or about modes of perception when you are in the middle of your first kiss.

Many of the Nazis were convicted after the war, but they were not convicted for being 'unreasonable'. They were convicted for being gruesome murderers.

But understanding will always require some effort. You probably wouldn't admire a friend who was good at everything if it cost her no effort.

Perhaps the clock hands had become so tired of going in the same direction year after year that they had suddenly begun to go the opposite way instead.

Throughout the entire history of philosophy, philosophers have sought to discover what man is - or what human nature is. But Sartre believed that man has no such eternal nature to fall back on. It is therefore useless to search for the meaning of life in general. We are condemned to improvise. We are like actors dragged onto the stage without having learned our lines, with no script and no prompter to whisper stage directions to us. We must decide for ourselves how to live.

It takes billions of years to create a human being. And it takes only a few seconds to die.

The most subversive people are those who ask questions.