QUI NON PROPULSAT - The Law Mind Legal Dictionary

QUI NON PROPULSATAuthored

The Law Mind • 570 words

Definition

Qui non propulsat injuriam quando potest, infert is a Latin maxim of law meaning: "He who does not repel an injury when he can, induces it." The principle holds that a party who has the power to prevent a wrong and fails to act is treated as having invited or caused that wrong. Passive allowance of harm, where the means to prevent it were available, is equated with active participation in bringing it about.

The maxim operates as a foundational rationale behind several legal duties — duties to mitigate, duties of care, and the broader principle that inaction can carry legal consequence when action was both possible and required.

Why It Matters in Research

This maxim appears in historical sources as a compressed statement of principle rather than a standalone rule. Researchers should treat it as doctrinal shorthand — a cipher pointing toward obligations that are developed elsewhere in the common law, not a self-executing rule with discrete elements.

The maxim surfaces most usefully when tracing the intellectual lineage of mitigation of damages, contributory negligence, and the duty to act in certain relationships. Historical treatise writers and courts invoked Latin maxims like this one to lend weight to propositions that were still hardening into doctrine. Finding this phrase in an older opinion or treatise is a signal to look laterally: what substantive rule was the author anchoring to this maxim?

Researchers working in the Law Mind corpus should note that Black's 2nd edition clusters this maxim with neighboring maxims in a dense, unpunctuated sequence — a formatting artifact of that edition's approach to Latin principles. The entry as printed runs this maxim directly into Qui obstruit aditum, destruit commodum and Qui omne dicit nihil excludit without clear visual separation, which can cause misreading. Each is a distinct maxim.

The Jenk. Cent. 271 citation in Black's refers to Jenkin's Centuries of Reports, a collection of cases decided in equity and common law courts, published in various editions from the seventeenth century onward. Researchers should verify which edition is accessible in a given archive, as pagination varies.

Historical Dictionary Support

Black's Law Dictionary (2nd Ed.) presents this as a bare maxim with its translation and the Jenkin's citation, offering no further elaboration. This is consistent with Black's treatment of Latin maxims generally in that edition: they are catalogued rather than analyzed, functioning as an index to primary sources rather than as definitions in the modern sense.

The maxim's substance — that failure to act when action was available is tantamount to causing the harm — reflects a principle with deep roots in both Roman law and English equity. Jenkyn's Centuries, the cited source, collected equity precedents and common law principles drawn from courts of the Tudor and early Stuart periods. The principle was well-established enough by that era to be recorded as received doctrine rather than as contested proposition.

Historical dictionaries do not meaningfully diverge on the translation or scope of this maxim. What they uniformly omit is any sustained analysis of when the duty to repel arises, how capacity to act is assessed, or how the principle interacts with competing doctrines — all of which must be reconstructed from primary sources.

QUI NON PROPULSATmain

Black's Law Dictionary (2nd Ed.) • 1910

Qui non propulsat injuriam quando potest, infert. Jenk. Cent. 271. He who does not repel an injury when he can, Induces it. Qui obstruit aditum, destrnit commodum. He who obstructs a way, passage, or entrance destroys a benefit or convenience. Co. Litt. 161¢. He who prevents another from entering upon land destroys the benefit which he has from it. Id. Qui omne dicit nihil excludit. 4 Inst. 81. He who says all excludes nothing. Qui parcit nocentibus innocentes punit. Jenk. Cent. 133. He who spares the guilty punishes the innocent. Qui pecoat ebrius luat sobrius. He who sing when drunk shall be punished when eober. Cary, 143; Broom, Max. 17. Qui per alium facit per seipsum facere videtur. He who does a thing by an agent is considered as doing it himself, Co. Litt. 258; Broom, Max. 817. Qui per fraudem agit frustra agit. 2 Rolle, 17. What a man does fraudulently he does in vain. Qui potest et debet vetare, jubet. He who can and ought to forbid a thing [if he do not forbid it] directs it. 2 Kent, Comm. 483, note. Qui primum peccat ille facit rixam. Godb. He who sins first makes the strife. Qui prior est tempore potior est jure. He who is before in time is the better in right. Priority in time gives preference in law. Co. Litt. 14¢; 4 Coke, 90a. A maxim of very extensive application, both at law and in equity. Broom, Max. 353-362; 1 Story, Eq. Jur. § 64d; Story, Bailm. § 312. Qui pro me aliquid facit nihi fecisse videtur. 2 Inst. 501. He who does anything for me appears to do it to me. Qui providet sibi providet hesredibus. He who provides for himself provides for his heirs. Qui rationem in omnibus gqusrunt rationem subvertunt. They who seek a reason for everything subvert reason. 2 Coke, 75; Broom, Max. 157, Qui sciens solvit indebitum donandi consilio id videtur feocisse. One who knowingly pays what is not due is supposed to have done it with the intention of making a gift. Walker v. Hill, 17 Mass. 388. Qui semel actionem renunciaverit amp ius repetere non potest. He who has