Jeremy Bentham, answered from the texts and cited to the page.
The principle is stated simply enough, though its implications are anything but simple: it is that principle which approves or disapproves of every action whatsoever according to the tendency that action appears to have to augment or diminish the happiness of the party whose interest is in question.1 Every action of a private individual, every measure of government — none is exempt from this test.2
I added, in a note of 1822, the fuller denomination: the greatest happiness or greatest felicity principle, meaning that principle which states the greatest happiness of all those whose interest is in question as being the right and proper, and only right and proper, and universally desirable end of human action.3 The word utility alone, I confess, does not so clearly point to the ideas of pleasure and pain, nor does it lead the mind to consider the number of interests affected — and it is that number which contributes in the largest proportion to the formation of the standard of right and wrong. Happiness, in turn, consists in the enjoyment of pleasures and security from pains.4
By utility is meant that property in any object whereby it tends to produce benefit, advantage, pleasure, good, or happiness — all this, in the present case, comes to the same thing — or to prevent the happening of mischief, pain, evil, or unhappiness to the party whose interest is considered.56 The magnitude of a pleasure is composed of its intensity and its duration: multiply the degrees of the one by the moments of the other, and you have the quantity.7
So too with pains, and with exemptions from pains. This is what I mean by applying arithmetical calculation to the elements of happiness — political arithmetic, as some have called it, though the name covers only a particular and far from all-comprehensive application of the method.8 To say the proper end of government is the greatest happiness of the greatest number is, as I put it in the preparatory work for the Constitutional Code, a declaration of peace and good will to all men.9
To say instead that the proper end is the greatest happiness of some one, or of some few, is to make a declaration of war against all the rest.10 There is the whole of politics in a sentence. Systems that attempt to question this principle deal in sounds instead of sense, in caprice instead of reason, in darkness instead of light.11
By the principle of utility is meant that principle which approves or disapproves of every action whatsoever, according to the tendency which it appears to have to augment or diminish the happiness of the party whose interest is in question.An Introduction to the Principles of Morals and Legislation, pp. 59–60
I say of every action whatsoever; and therefore not only of every action of a private individual, but of every measure of government.An Introduction to the Principles of Morals and Legislation, pp. 59–60
To this denomination has of late been added, or substituted, the greatest happiness or greatest felicity principle: this for shortness, instead of saying at length that principle which states the greatest happiness of all those whose interest is in question, as being the right and proper, and only right and proper and universally desirable, end of human action.An Introduction to the Principles of Morals and Legislation, pp. 59–60
The word utility does not so clearly point to the ideas of pleasure and pain as the words happiness and felicity do: nor does it lead us to the consideration of the number, the interests affected; to the number, as being the circumstance, which contributes, in the largest proportion, to the formation of the standard here in question.An Introduction to the Principles of Morals and Legislation, pp. 59–60
happiness... consists of enjoyment of pls. and security from pn.An Introduction to the Principles of Morals and Legislation, pp. 368–369
By utility is meant that property in any object, whereby it tends to produce benefit, advantage, pleasure, good, or happiness, (all this in the present case comes to the same thing) or (what comes again to the same thing) to prevent the happening of mischief, pain, evil, or unhappiness to the party whose interest is considered.An Introduction to the Principles of Morals and Legislation, pp. 59–60
The magnitude—the greatness—of a pleasure, is composed of its intensity and its duration: to obtain it, supposing its intensity represented by a certain number of degrees, you multiply that number by the number expressive of the moments or atoms of time contained in its duration.Legislator of the World, Writings on Codification, Law, and Education, p. 313
Political arithmetic—a name that has by some been given to political economy—is an application, though but a particular and far short of an all-comprehensive one, of arithmetic and its calculations, to happiness and its elements.Legislator of the World, Writings on Codification, Law, and Education, p. 313
Say in other words, the greatest happiness of the greatest number... were I to say the proper end of government is the greatest happiness of the greatest number, it seems to me that I have made a declaration of peace and good will to all men.First Principles Preparatory to Constitutional Code, pp. 280–281
On the other hand were I to say the proper end of government is the greatest happiness of some one, naming him, or of some few, naming them, it seems to me that I should be making a declaration of war against all men, with the exception of that one or of those few.First Principles Preparatory to Constitutional Code, pp. 280–281
Systems which attempt to question it, deal in sounds instead of sense, in caprice instead of reason, in darkness instead of light.An Introduction to the Principles of Morals and Legislation, pp. 59–60