Ethical hedonism was originally tied to psychological hedonism about human motivation. Bentham assumed that all humans are basically and exclusively motivated by the desire to gain pleasure and avoid pain, but it is possible to maintain ethical hedonism while rejecting, as most present utilitarians are inclined to do, psychological hedonism. However, certain later and contemporary versions of utilitarianism broaden the notion of ethical hedonism so that human or personal good is understood to be constituted by whatever satisfies people's desires or preferences or makes people happy.