What matters, rather than intention, is the outcome of actions. We justify the value of our deeds only on their results, be they useful, beneficial, or detrimental. This is how utilitarianism looks at actions and it stands in stark contrast with deontology (Kant’s brand of morality), which on the contrary values intention over consequence. In this sense, utilitarianism is a type of consequentialism.
The main names behind utilitarianism are Jeremy Bentham and John Stuart Mill. Utility is the sum of all pleasure that results from an action, minus the suffering of anyone involved in the action, says Bentham. JS Mill tells us that we must always act so as to produce the greatest aggregate happiness among all sentient beings.
What is happiness?
Happiness, for the utilitarian, is none other than the production of pleasure and the lack of pain.
When moral agents –someone with the ability to recognise right from wrong– are given the choice between two or more actions, they ought to choose the action that maximises the total happiness.
In other words, between two choices X and Y, if X brings more happiness, or at least less pain, then the utilitarian should conclude that X produces more utility, and is therefore favourable to, Y, and should likewise choose the X course of action.
Should the moral agent have even more options to choose from, say, X, Y, and Z, then it follows that the right choice is the one that is in proportion as it tends to promote happiness. Conversely, it is wrong as it tends to produce the reverse of happiness, such as pain or privation of that happiness.
How do we best find happiness? By learning how to limit our desires, rather than attempting to satisfy them.