Definition
Latin: "by human industry." A doctrine from old English property law describing the means by which a person could acquire a qualified possessory right in wild animals (ferae naturae) through taming, reclaiming, or training them. Because wild animals are by nature unowned, the law recognized that sustained human effort — domestication, education, and art — could give rise to a legally cognizable interest that would not otherwise exist in an untamed creature. The property acquired per industriam hominis is qualified rather than absolute: if the animal escapes and returns to its wild state, the possessory right is extinguished.
Common Confusion
Per industriam hominis is frequently encountered alongside two related doctrines that researchers must keep distinct. First, property ratione soli refers to a landowner's possessory right to take wild animals on their own land — a right grounded in land ownership rather than personal effort. Second, property per animus revertendi describes a qualified property right in semi-domesticated animals that have developed a habit of returning to the owner, such as homing pigeons or domestic bees. The per industriam doctrine differs from both: it attaches specifically to the labor of taming and is personal to the trainer or keeper, not derived from land or habit of return.
Core Elements
To establish a qualified property right per industriam hominis, the traditional elements are:
1. Wild animal (ferae naturae): The doctrine applies only to animals that are by nature wild and unowned. It has no application to domestic animals, which are the subject of ordinary absolute property rights.
2. Human industry: The right arises from affirmative, sustained effort — training, taming, or reclaiming — not mere capture or temporary confinement alone.
3. Continued control or reclamation: The qualified right persists only while control is maintained or while the animal retains the acquired habit. Return to the wild terminates the right.
Why It Matters in Research
This term appears almost exclusively in historical English property law sources and is of limited direct application in modern American or English courts. Researchers will encounter it most often in treatises tracing the origins of wildlife law, the common law of animals, and the roots of modern property doctrine.
The primary navigational challenge is that per industriam hominis is part of a cluster of Latin maxims governing ferae naturae — wild animals — that the historical sources treat interchangeably or in rapid succession. Bouvier's entry, for example, immediately follows the term with per infortunium (homicide by misadventure), creating a risk of context bleed when reading across entries in sequence. Researchers working with Bouvier's must be careful to isolate the correct entry.
The Blackstone reference (2 Bl. Comm. 391) is the authoritative anchor for all four source dictionaries, and researchers who need depth should proceed directly to Blackstone. All four dictionary entries essentially summarize rather than extend Blackstone's analysis. No source adds independent doctrinal content.
For researchers tracing modern wildlife law, hunting regulations, or the public trust doctrine, per industriam hominis represents an early common law precursor to the state's regulatory claim over wild animals. The qualified-property framework it describes was largely absorbed or displaced by statutory wildlife regimes in the nineteenth and twentieth centuries, but the underlying logic — that unowned things become property only through human act — persists in related modern contexts including domestication of animals, capture of wild fish, and certain intellectual property analogies.
Historical Dictionary Support
All four source dictionaries — Black's (both editions), Bouvier's, and Burrill's — are in complete agreement. Each defines the term as "by human industry" and describes it as applying to the reclaiming or taming of wild animals by art, industry, and education. All four cite 2 Bl. Comm. 391 as the sole authority. There is no divergence among the sources on definition, application, or scope.
The uniformity is itself informative: it confirms that per industriam hominis was a term of art with a settled, narrow meaning rather than a contested or evolving concept. None of the dictionaries extends the doctrine beyond its Blackstone formulation, and none addresses whether or how the doctrine applied in American jurisdictions. Researchers should treat the American application as an open question requiring independent source work beyond the historical dictionaries.
Jurisdictional Note
The doctrine originates in English common law and was articulated primarily through Blackstone. American courts received the common law framework for ferae naturae but modified it substantially through state and federal wildlife statutes. The per industriam doctrine as a standalone common law rule has little direct modern application in U.S. jurisdictions, though its underlying logic surfaces in cases involving escaped domesticated animals and in early American hunting and trapping disputes.