Ignorance of the law excuses no man; not that all men know the law, but because ’tis an excuse every man will plead, and no man can tell how to refute him.

John Selden (1584–1654), an English jurist, antiquary, and Member of Parliament, is closely associated with the maxim that ignorance of the law is no excuse. The quoted formulation is preserved not from a formal treatise but from Selden’s table talk—witty, aphoristic remarks recorded from conversation late in his life. In seventeenth-century England, as statutory and common law grew increasingly complex, the legal system still relied on the practical necessity that courts could not allow defendants to escape liability by claiming they did not know the rules. Selden’s remark explains the policy logic behind the doctrine: it is less a claim about universal legal knowledge than a safeguard against an unfalsifiable defense.

Selden reframes a seemingly harsh legal principle as a pragmatic rule of administration. He concedes the obvious—no one can actually know all the law—yet argues that allowing ignorance as a defense would make enforcement impossible, because the claim is easy to assert and difficult to disprove. The quote highlights a tension between fairness (punishing people for rules they may not know) and governability (maintaining a workable system where rules can be applied consistently). It also implies a skeptical view of human self-interest: if a loophole exists, “every man will plead” it. The significance lies in its candid articulation of legal policy rather than moral idealism.

1) “Ignorance of the law excuses no man; not that all men know the law, but because ’tis an excuse every man will plead, and no man can tell how to confute him.”
2) “Ignorantia juris non excusat.”
3) “Ignorance of the law is no excuse.”