Utilitarianism is a family of ethical theories that prescribe actions which maximize happiness and well-being for all affected individuals. It was founded by Jeremy Bentham and further developed by John Stuart Mill. Bentham viewed utility as anything producing benefit, pleasure, or preventing pain, while Mill considered both quantity and quality of pleasure. Utilitarianism's core principles are: 1) pleasure/happiness is intrinsically valuable, 2) actions are right if they promote happiness and wrong if they cause unhappiness, and 3) everyone's happiness counts equally. Critics argue it is impractical to consider only consequences and not actions themselves, or to treat all individuals' happiness as equally important.