The brain and the eye may have a contractual relationship in which the brain has agreed to believe what the eye sees, but in return the eye has agreed to look for what the brain wants.

The mistakes we make when we try to imagine our personal futures are also lawful, regular, and systematic. They, too, have a pattern that tells us about the powers and limits of foresight in much the same way that optical illusions tell us about the powers and limits of eyesight.

Alas, we think of ourselves as unique entities-minds unlike any others-and thus we often reject the lessons that the emotional experience of others has to teach us.

Few of us can accurately gauge how we will feel tomorrow or next week. That's why when you go to the supermarket on an empty stomach, you'll buy too much, and if you shop after a big meal, you'll buy too little.

The word happiness is used to indicate at least three related things, which we might roughly call emotional happiness, moral happiness, and judgmental happiness.

People want to be happy, and all the other things they want are typically meant to be a means to that end.

The good news is that going blind is not going to make you as unhappy as you think it will. The bad news is that winning the lottery will not make you as happy as you expect.