Quotes from book
An Introduction to the Principles of Morals and Legislation

An Introduction to the Principles of Morals and Legislation is a book by the English philosopher and legal theorist Jeremy Bentham "originally printed in 1780, and first published in 1789." Bentham's "most important theoretical work," it is where Bentham develops his theory of utilitarianism and is the first major book on the topic.

“The question is not Can they reason?, nor Can they talk?, but Can they suffer?”
Source: An Introduction to the Principles of Morals and Legislation (1789; 1823), Ch. 17 : Of the Limits of the Penal Branch of Jurisprudence
Source: The Principles of Morals and Legislation
Context: The day has been, I grieve to say in many places it is not yet past, in which the greater part of the species, under the denomination of slaves, have been treated by the law exactly upon the same footing as, in England for example, the inferior races of animals are still. The day may come when the rest of the animal creation may acquire those rights which never could have been withholden from them but by the hand of tyranny. The French have already discovered that the blackness of the skin is no reason why a human being should be abandoned without redress to the caprice of a tormentor. It may one day come to be recognized that the number of legs, the villosity of the skin, or the termination of the os sacrum are reasons equally insufficient for abandoning a sensitive being to the same fate. What else is it that should trace the insuperable line? Is it the faculty of reason, or perhaps the faculty of discourse? But a full-grown horse or dog is beyond comparison a more rational, as well as a more conversable animal, than an infant of a day or a week or even a month, old. But suppose they were otherwise, what would it avail? The question is not Can they reason?, nor Can they talk?, but Can they suffer?

Source: An Introduction to the Principles of Morals and Legislation (1789; 1823), Ch. 1 : Of the Principle of Utility
Context: 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 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.

Source: An Introduction to the Principles of Morals and Legislation (1789; 1823), Ch. 17 : Of the Limits of the Penal Branch of Jurisprudence
Context: The day has been, I grieve to say in many places it is not yet past, in which the greater part of the species, under the denomination of slaves, have been treated by the law exactly upon the same footing as, in England for example, the inferior races of animals are still. The day may come when the rest of the animal creation may acquire those rights which never could have been withholden from them but by the hand of tyranny. The French have already discovered that the blackness of the skin is no reason why a human being should be abandoned without redress to the caprice of a tormentor. It may one day come to be recognized that the number of legs, the villosity of the skin, or the termination of the os sacrum are reasons equally insufficient for abandoning a sensitive being to the same fate. What else is it that should trace the insuperable line? Is it the faculty of reason, or perhaps the faculty of discourse? But a full-grown horse or dog is beyond comparison a more rational, as well as a more conversable animal, than an infant of a day or a week or even a month, old. But suppose they were otherwise, what would it avail? The question is not Can they reason?, nor Can they talk?, but Can they suffer?