Definition
In patent law, one who conceives of a new and useful invention — a new art, manufacture, machine, composition of matter, or process — and who is entitled, as against all others, to apply for and receive a patent for that invention. The inventor is the person who contributes the original conception of the claimed invention, not merely one who assists in its reduction to practice, provides funding, or carries out the inventor's instructions.
Where two or more persons each contribute to the conception of a patented invention, they are joint inventors, and each holds an undivided interest in the resulting patent regardless of the relative weight of each person's contribution.
Common Language
Modern common usage (Wiktionary): One who invents, either as a hobby or as an occupation.
Historical common usage (Webster's 1913): One who invents or finds out something new; a contriver; especially, one who invents mechanical devices.
The common meaning tracks the legal meaning closely but misses the critical legal distinction: in patent law, inventorship is not about who builds, funds, or promotes a new device — it is specifically about who conceives the claimed invention. A skilled machinist who constructs a prototype from an engineer's detailed drawings is not, in the legal sense, an inventor, even though ordinary usage might loosely describe the work as inventive. This gap between popular and legal meaning is a persistent source of inventorship disputes.
Common Confusion
INVENTOR vs. ASSIGNEE: The inventor is the natural person who conceives the invention. The assignee is the entity — often an employer or corporation — that holds ownership rights after the inventor has transferred them by agreement. Corporations cannot be inventors; they can only be assignees. Historical sources and many commercial contracts blur this line, particularly in employment contexts.
INVENTOR vs. DISCOVERER: Legal patent systems have traditionally distinguished invention (creating something new) from discovery (finding something that already exists in nature). A natural phenomenon or law of nature, however novel its identification, does not produce an inventor in the patent sense. This distinction has sharpened considerably in modern patent doctrine and is largely absent from the historical dictionary entries below.
Why It Matters in Research
Inventorship is a legal determination, not a biographical or commercial one, and this creates significant navigational complexity in historical sources. Nineteenth-century patent literature, including the dictionary definitions collected here, treats "inventor" loosely as anyone who "finds out or contrives" something new. Modern patent law has hardened this into a formal test centered on conception of the claimed subject matter. Researchers working with pre-twentieth-century materials should be alert to this looser usage.
Inventorship also changed dramatically in practice following the rise of industrial research laboratories and corporate employment. Sources from the mid-nineteenth century assume the inventor and the patent applicant are typically the same individual. By the early twentieth century, patent assignment to employers had become standard practice, producing a split between nominal inventor (the employee named on the patent) and effective owner (the corporate assignee). The dictionary definitions here predate that shift and give no indication of it.
Joint inventorship is another area where historical sources provide little guidance. Modern doctrine requires that each joint inventor contribute to the conception of at least one claim; historical sources treat joint invention only briefly, if at all.
Researchers using Law Mind corpus materials should also note that "inventor" as used in older patent treatises and digests may encompass the first importer of a foreign invention into a domestic market — a category recognized under early English patent practice and some colonial American law, but abandoned in modern U.S. patent doctrine. Bouvier's implicit cross-reference to PATENT is the appropriate starting point for tracing this historical usage.
Historical Dictionary Support
All three source dictionaries converge on the core meaning: an inventor is one who contrives or produces something new. Black's (both editions) frames this around utility — new arts, manufactures, mechanical appliances, processes — language that tracks the statutory subject matter categories of early U.S. patent law. Bouvier adds the useful clarification that the word is "generally used to denote the author of such contrivances as are by law patentable," which signals awareness that not every colloquial inventor qualifies in a legal proceeding.
Black's 2nd edition references Henderson v. Tompkins and Sparkman v. Higgins, cases dealing with patent validity and inventorship questions in the federal circuit courts. These are useful period sources for understanding how courts of that era applied the term in litigation, though their doctrinal authority is now only historical.
None of the historical dictionary entries addresses the conception-versus-reduction-to-practice distinction that became central to inventorship doctrine, nor do they treat joint inventorship in any substantive way. Researchers should treat these definitions as accurate for their period but insufficient for analyzing modern patent questions or disputes arising after the early twentieth century.
Jurisdictional Note
In the United States, inventorship is governed by federal patent law and is uniform across states. Other common-law jurisdictions — including the United Kingdom, Canada, and Australia — have their own statutory definitions of inventor that broadly align with the U.S. conception-based standard but differ in procedural requirements and the treatment of employed inventors' rights. Researchers working with international patent materials should not assume U.S. doctrine maps cleanly onto foreign systems.
Encyclopedia Cross-Reference
See Law Mind Encyclopedia: Patent Law; Joint Inventorship; Conception and Reduction to Practice.