Utilitarianism links morality to the maximization of human happiness. Two issues dominate modern utilitarianism. What is happiness? How is morality linked to happiness? The first question is the topic of this chapter.

The classical utilitarians were all, in different ways, hedonists. For them, happiness is pleasure (and the absence of pain). While hedonism still has its defenders, most modern utilitarians favour alternative views. This has led to a change in terminology. “Happiness” is thought to bias the discussion in favour of hedonism. Modern utilitarian philosophers talk in more neutral terms: well-being, welfare, “whatever makes life worth living”; while utilitarian economists tend to use Bentham's technical term utility.

We all think about well-being all the time. When we ask whether some particular experience will be good or bad; when you look back on your life and list the things that made it go well and those that made it go badly; when you compare the situations of two different people and ask who is better-off; when a friend seeks your advice on a major life choice, and you ask what would be better for her; when I look forward and ask whether my life will go better if I become a lawyer or a philosopher. Many things can make a life go better: pleasure, money, achievement, health, freedom. Many things can make a life go worse: pain, frustration, poverty, disappointment, grief.