Definition
Justifiable means rightful, warranted, or sanctioned by law — conduct that can be shown to be legally sustained, such that no liability or punishment attaches. An act is justifiable when the law not only excuses but affirmatively permits it, recognizing the conduct as lawful under the circumstances. The term appears most prominently in compound constructions: justifiable homicide, justifiable force, justifiable cause.
Common Language
Modern common usage (Wiktionary): That which can be justified; describing an illegal and intentional act that is nevertheless not blameworthy because its positive consequences outweighed the bad. Distinguished from excusable, describing an involuntary illegal act.
Historical common usage (Webster's 1913): Capable of being justified, or shown to be just.
The common-language definitions treat justifiable as a general moral or practical judgment — something defensible on rational grounds. The legal definition is narrower and more demanding: conduct is justifiable only when it is affirmatively warranted by law, not merely understandable or morally defensible. The Wiktionary entry usefully flags the legal distinction between justifiable and excusable acts, which is critical in criminal law doctrine.
Common Confusion
JUSTIFIABLE VS. EXCUSABLE
These terms are frequently conflated but carry distinct legal weight. A justifiable act is one the law treats as lawful and proper — the actor did nothing wrong. An excusable act is one that was technically wrongful but for which the law withholds punishment because of the circumstances (duress, mistake, incapacity). The distinction matters for civil liability: a justified actor faces no civil exposure, while an excused actor may still be liable in tort. In many older authorities, the two categories were loosely blended; modern criminal law treats them as separate defenses.
Why It Matters in Research
The term "justifiable" in historical sources almost always functions as a modifier, not a standalone concept. Researchers will rarely find "justifiable" as an independent subject of legal analysis — look for it as part of compound terms: justifiable homicide, justifiable use of force, justifiable cause for termination, or justifiable reliance. Each of these compounds has its own developed doctrine.
In historical sources, justifiable homicide is the primary context in which the term receives substantive treatment. Researchers examining older case law or treatises on homicide should be aware that the category of "justifiable homicide" was significantly broader in earlier periods and included acts that modern law might classify as excusable, or might not treat as homicide at all (e.g., execution by public authority). The line between justifiable and excusable homicide shifted considerably between the nineteenth century and modern statutes.
The term also appears in equity and contract contexts — "justifiable cause" and "justifiable reliance" — where it signals that a party's action or belief had an objectively sufficient legal basis. In these contexts, justifiable operates as an objective standard, not a subjective one: what a reasonable person in the circumstances would have been warranted in doing or believing.
Corpus navigation note: Because the term functions primarily as a modifier, searching for "justifiable" alone will return scattered results across many doctrinal areas. Searches should be paired with the noun modified. Anderson's Dictionary of Law routes researchers immediately to BATTERY and HOMICIDE, which is the correct navigational instinct for most historical research involving this term.
Historical Dictionary Support
The four shelf sources are notably thin on independent treatment of "justifiable," which itself signals something important: historical legal lexicographers treated the term as self-explanatory or as subsumed within the entries it modified.
Both Black's editions give identical, brief definitions — "rightful; warranted or sanctioned by law; that which can be shown to be sustained by law" — and both use justifiable homicide as the only illustrative example, directing researchers elsewhere. Black's first edition appends two maxims on justice (justitia est constans et perpetua voluntas jus suum cuique tribuendi; justitia est duplex) that illuminate the underlying concept but do not define the term with greater precision. Their inclusion suggests the original editors saw the term as closely tied to the broader Latin tradition of justice as giving each person their due.
Rapalje & Lawrence approach the term through the doctrine of justification as a defense in tort — specifically in the context of battery and breaches of the peace — noting that a defendant who raises a lawful basis for otherwise tortious conduct "is said to justify." This is a procedurally meaningful framing: justification is not merely a moral claim but a pleaded defense, historically requiring the defendant to affirmatively set it up. This procedural dimension — that justification must be shown and sustained, not merely asserted — aligns with Black's formulation that conduct must be "shown to be sustained by law."
Anderson's cross-reference to BATTERY and HOMICIDE confirms that the term's legal substance lives in those doctrinal entries, not in a freestanding definition of "justifiable."
No shelf source draws the justifiable/excusable distinction explicitly, which reflects the historical blurring of those categories. Modern researchers should not assume older authorities maintained the clean separation that contemporary criminal law doctrine requires.