An Introduction to the Principles of Morals and LegislationJeremy Bentham

Bentham wrote An Introduction to the Principles of Morals and Legislation as the preface to a penal code he never finished, and it reads like one: definitions, numbered cases, division carried out to the end. The opening sentence sets the terms. Nature has placed mankind under the governance of two sovereign masters, pain and pleasure, and the principle of utility approves or disapproves of any action according to its tendency to increase or diminish the happiness of the party whose interest is in question. The rival principles, asceticism and sympathy and antipathy, get dismissed in a chapter apiece.

Chapter IV supplies the measuring instrument. A pleasure or a pain has intensity, duration, certainty, propinquity, fecundity, and purity, and when a community is at stake it also has extent. Chapter V catalogues the simple pleasures and pains themselves, fourteen of the one and twelve of the other, on the assumption that moral quantities can be enumerated like any others. Bentham admits no distinction of higher and lower, which is the point Mill takes up against him in Utilitarianism.

The later chapters turn to law. Motives are never bad in themselves; only their effects are. Intention, consciousness, and disposition matter to sentencing insofar as they bear on future deterrence. Punishment is itself an evil, admitted only to shut out a greater one, so Bentham lists the cases where it should not fall: where the mischief is groundless, where punishment cannot act on the will, where it costs more than it prevents, where the end can be had without it.

One footnote extends the calculus past our own species. Of animals Bentham asks not whether they can reason, nor whether they can talk, but whether they can suffer.