I. Nature has placed mankind under the governance of two sovereign masters, pain and pleasure. It is for them alone to point out what we ought to do, as well as to determine what we [actually] shall do. On the one hand the standard of right and wrong, on the other the chain of causes and effects, are fastened to their throne. They govern us in all we do, in all we say, in all we think: every effort we can make to throw off our subjection, will serve but to demonstrate and confirm it. In words a man may pretend to abjure their empire: but in reality he will remain subject to it all the while. The principle of utility recognizes this subjection, and assumes it for the foundation of that system the object of which is to rear the fabric of felicity by the hands of reason and of law. Systems, which attempt to question it, deal in sounds instead of sense, in caprice instead of reason, in darkness instead of light.

But enough of metaphor and declamation: it is not by such means that moral science is to be improved.

II . . . 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: or, what is the same thing in other words, to promote or to oppose that happiness. I say of every action whatsoever; and therefore not only of every action of a private individual, but of every measure of government.

III. By utility is meant that property in any object, whereby it tends to produce benefit, advantage, pleasure, good, or happiness, (all this . . . comes to the same thing) or (what again comes to the same thing) to prevent the happening of mischief, pain, evil, or unhappiness to the party whose interest is considered: if that party be the community in general, then the happiness of the community: if a particular individual, then the happiness of that individual.

IV. The interest of the community . . . is . . . the sum total of the interests of the several members who compose it.

V. It is vain to talk of the interest of the community, without understanding what is the interest of the individual. A thing is said to promote the interest, or to be for the interest, of an individual, when it tends to add to the sum total of his pleasures: or, what comes to the same thing, to diminish the sum total of his pains.

VI. An action then may be said to be conformable to the principle of utility...when the tendency it has to augment the happiness of the community is greater than any it has to diminish it. . . .

X. Of an action that is conformable to the principle of utility, one may always say either that it is one that ought to be done, or at least that it is not one that ought not to be done. One may say also, that it is right it should be done; at least that it is not wrong it should be done: that it is a right action; at least that it is not a wrong action. When thus interpreted, the words ought, and right and wrong, and others of that stamp have a meaning: when [interpreted] otherwise, they have none.

I. Pleasures then, and the avoidance of pains, are the ends which the legislator has in view: it behooves him therefore to understand their value. . . .

V. To take an exact account . . . of the general tendency of any act. . . .[:]

Sum up all the values of the pleasures on the one side, and those of all the pains on the other. The balance, if it be on the side of pleasure, will give the good tendency of the act upon the whole. . . .