Utilitarianism is an ethical theory with a long and distinguished history. It is a species of consequentialism, the theory that tells us we should seek to act in ways that will maximize the goodness or value of the consequences of our actions. As G. E. Moore dramatically put it, “Our ‘duty’… can only be defined as that action, which will cause more good to exist in the Universe than any possible alternative.” What makes utilitarianism distinctive is its understanding of what goodness or value consists in, namely happiness or utility.