Blackstone claimed that the English constitution was the accumulated wisdom of centuries and therefore not to be tampered with by reformers. Bentham identifies this as circular reasoning: it presupposes that whatever has survived is wise, and that wisdom is whatever has survived. The Fragment strips the conservative fallacy bare, showing that tradition is not a moral argument but an evasion of one. Laws must be judged by what they do to human happiness — not by how old they are.
Bentham also challenges the social-contract foundation that underpinned much Enlightenment political theory. The notion of an original contract between the governed and their governors is, he argues, a fiction — and a dangerous one, because it grounds political obligation on an event that never occurred. Political authority rests on habit and utility alone: people obey government when the probable mischiefs of disobedience outweigh the probable mischiefs of submission. The criterion is always consequences, never ancestry.
The Fragment on Government (1776) was published anonymously; Bentham was revealed as its author only after initial praise from figures who had assumed a more established writer.