How does Locke’s theory of property apply to copyrights? It applies in the same way that Newtonian physics applies to relativistic or quantum-scale events. It applies badly, in other words, giving uncertain and even misleading results. The essay under review, alas, offers ample proof of that effect. We would do better to reserve Locke’s property theory for understanding the proper scope of rights in tangibles, and use his theory of politics to understanding the proper scope of copyrights. On that view, copyright is not a form of property arising in nature but a type of privilege arising by state fiat.
Newtonian physics does a perfectly fine job of explaining the world at the scale of dust, humans, and stars. Engineers trust in it utterly when they design bridges and airplanes. So, too, for Lockean theory. We can trust it to explain how property rights first arise in a state of nature; how the sweat of our brows becomes the bread on our tables.
But even the biggest fans of Newtonian physics (and I count myself among them) have to admit that it has limits. It does not do a good job of modeling the physics of relativistic or quantum-scale events—particles traveling near the speed of light or particles the size of a, say, a gluon. We can only imagine how Newton would have explained phenomena at those extremes; as it was, he lacked even the instruments to observe them.
We honor Isaac Newton, as we honor John Locke, for acts of monumental genius and creativity. We owe both more than we can ever repay. But we do not honor such men by abusing their theories.
Locke’s theory of property works perfectly well to explain how rights in tangible property arise. When latter-day thinkers stretch Locke’s theory to intangible assets, however, the fit grows awkward and the results untrustworthy. That is not fault of Locke. He lived in an era when copyrights as we know them did not exist. And what little Locke did say about the topic demonstrates that he did not think that authors had natural rights to their original expressions.
We of course cannot know what Locke actually thought about copyrights. We can only do our best to decipher his written comments about authors’ rights in their expressions. A fair review of the relatively scant literature—a few comments by Locke on existing and proposed legislation—finds him very far from equating copyrights to property. Very far, indeed. Rather more on the other side of the issue, in fact.
Professor Mossoff’s essay offers a contrasting account of Locke, one that portrays him as a full-throated proponent of copyright-qua-property. He writes that “Locke himself expressly recognizes that copyright is property.” But his essay never convincingly links Locke’s actual words to this interpretation. The claim just quoted, for instance, has no supporting citation.
A similarly troubling lack of rigor recurs throughout the essay. It would prove more tiresome than illuminating to document these deficiencies, were not so much at stake. The words of Locke, that giant of classical liberal thought, merit our closest attention and highest regard.
Not long after that first breezy characterization of Locke’s views, the essay returns to the theme, this time including what looks like backing proof:
Locke himself expressly justifies copyright as “property” and approvingly refers to “Inventions and arts” in his summation of his theory that property arises from value-creating, productive labor that supports the “conveniences of life” in § 44 of the Second Treatise.
He does not even mention copyright in the cited section of the Second Treatise, however, once again leaving a bold claim about Locke’s embrace of copyright undocumented. Nor does the loose talk end there; the next paragraph claims that “Locke expressly endorses [copyright] as a property right in 1695.” No footnote or cite follows, but the date gives readers a clue that they should probably refer to one or more of the three essays that Locke penned from around late 1694 through March 1695. Exactly what parts of those essays (if any) support the claim about Locke’s embrace of copyright remains unclear.
A citation to Locke’s actual writings finally comes in the footnote supporting the claim, “Locke condemns [the Stationers Company] monopoly as violating the ‘property’ in creative works that ‘authors’ rightly claim for themselves.” But whence come the quoted terms? And more importantly, in what context do they appear?
Again, the essay under review does not say. Let us take a moment fill that lacuna. The exercise, though painstaking, reveals quite a lot about what Locke thought—or more accurately, what he did not think—about copyright.
An electronic search of the Locke’s critique of the Stationers Company Act uncovers only two uses of the word “property.” The first comes in a passage where Locke, far from worrying about authors’ rights in their original expressions, describes the Licensing Act—the closest thing in his day to a Copyright Act—as a “manifest  invasion on the trade, liberty, and property” of those subjected to its censorious effects. The second use of “property” in Locke’s critique finds him not lauding the privilege that licensed publishers had to restrict the copying of subject works but rather suggesting “limiting their property to a certain number of years after the death of the author or the first printing of the book as suppose 50 or 70 years.” Locke thus referred to the supposed property of licensed publishers rather than authors, and he mentioned it only to ensure it did not go too far.
A similar search for “author” likewise undercuts the claim that Locke’s critique of the Stationer Company Act argues for a natural rights to copyright. The term “authors” appears twice in the cited pages, but on both occasions Locke refers to ancient rather than modern authors. And about ancient authors, Locke leaves no doubt that he regards any copyright-like restriction as utterly unjustifiable. “That any person or company should have patents for the sole printing of ancient authors is very unreasonable and injurious to learning,” Locke pronounces.
The essay under review saves its most convincing evidence that Locke extended his property theory to copyrights for the last, when it quotes his call for adding to a draft bill aimed at reforming the Stationers Company, and submitted for his commentary, an amendment designed to “secure the author’s property in his copy, or his to whom he has transferred it.” Even this, however, does not establish that Locke regarded copyright as a natural right.
First, note that Locke does not speak of an author’s property in his work—a term that in copyright law refers to an author’s expression in the abstract—but rather his property in his copy—a term that refers to a particular material embodiment of the work. Second, note that Locke’s call for protecting an author’s copy apparently aims to do nothing more than codify the right, at that time recognized at common law, of an author to restrict reuse of his or her tangible, unpublished manuscript. Third, note that when it comes to the actual language of his proposed amendment, Locke says not that it should secure an author’s property rights, but that it should “vest a privilege in the author of . . . solely reprinting and publishing” the book.
So this last and best effort to secure Locke as a champion of copyright, like the earlier ones, fails.
Insofar as we can discern anything about Locke’s views on copyright, he hardly seemed predisposed toward it. His critique of the Stationers Company resounds with complaints against the harsh remedies levied against those who merely happen to possess an illicit book:
How the gentlemen, much more how the peers, of England came thus to prostitute their houses to the visitation and inspection of anybody . . . upon pretence [sic] of searching for books, I cannot imagine.
Note that Locke’s objection has nothing to do with the Stationers Company itself; the objection instead speaks to the lack of proportion between the remedies deployed and the end—the regulation of books—to be achieved. Locke might have made the same objection against the present Copyright Act, which imposes still worse sanctions. It entails, in the service of similar aims, not just the search for and seizure of infringing works, but even criminal penalties.
Locke also celebrated the free-wheeling publishing industry of the Dutch Republic, which did not get a copyright law until 1803, without voicing any evident concern about how all that unauthorized reprinting affected authors’ property rights. It is hard to imagine Locke speaking so approvingly of a den of thieves reselling stolen wares.
In sum, Locke does not appear to have regarded copyrights as a form of property capable of arising in a state of nature from the mixture of labor with unowned materials. He was too smart for that. Lockean property theory, having been based on examples from the physical world and having been formulated with an eye to justifying rights in real estate and chattels, simply does not fit copyrights very well. As the reviewed essay observes, that lack of fit did not stop early American courts and legal commentators from sometimes applying Locke’s theory to copyrights. They evidently, and unsurprisingly, were not as smart as Locke.
Happily, however, the 19th century vogue for taking Locke too far in judicial deliberations about copyright has now largely passed. For that, we can credit progress in the social sciences. Since Locke’s day, economists have come to understand that copyright, not being rivalrous in consumption, differs fundamentally from conventional, tangible assets. That fundamental difference justifies understanding copyrights not as a form of property, but as a form of privilege.
So much of this response has focused on setting the record straight about what Locke thought about copyrights that little room remains to describe what we should think about it ourselves. Suffice it here to say that Locke does hold the answers. We must look for them not in his theory of property, however, but in his theory of politics. There, as we see in his critique of the Licensing Act, Locke counsels skepticism about the wisdom of granting special privileges to a select few at the expense of everyone else’s natural rights. Today, we should follow Locke both in recognizing property in tangibles and in defending those natural rights from mere privileges that instead advance state power at the expense of individual liberty.
 Though this essay focuses on copyright, many of the more general observations apply ceteris paribus to patents.
 See John Locke: Political Essays, edited by Mark Goldie (Cambridge University Press, 1997), pp. 327-39. In those pages, Goldie collects three essays under the label, “Liberty of the Press,” at least two of which date from 1695. (Hereafter cited as “Political Essays.”)
 The footnote, here elided, refers to Political Essays pp. 330-38, a span which somewhat confusingly includes not just Locke’s criticisms of the Licensing Acts of 1662 but also his summary of a draft Bill for Better Regulating Printing and a portion of his amendments to it.
 Ibid., p. 336.
 Ibid., p. 337. Although Mossoff reads this to mean that “authors should have their property rights secured to them for their lifetimes or after first publication plus ‘50 or 70 years,’” it seems much more plausible to read Locke as saying the term should be death of the author plus 50 years or the first printing plus 70. The “as suppose” in the subject sentence creates a parallelism between “the death of the author or the first printing of the book” and the proposed terms of “50 or 70 years.” Such syntactic structures were common in the era. See, for example, the Constitution’s patent and copyright clause (Article 1, Section 8, Clause 8). So understood, Locke’s bifurcated structure resembles that used in the present Act for works for hire, pseudonymous, or anonymous works, which last for the shorter of creation plus 120 or publication plus 95. See 17 U.S. Code, Section 302(c).
 Charitably broadening the search to “author” does not change matters.
 Again, see Political Essays, p. 333 (“ancient Latin authors”); and p. 337 (“ancient authors”).
 Ibid., p. 337, and also p. 333 (complaining that the Licensure Act leaves the right to publish ancient authors in the “power of those dull wretches who do not so much as understand Latin”).
 Ibid., p. 337. In fact, Mossoff misquotes Locke as saying, ungrammatically, “or to his whom . . . .”
 Compare 15 U.S. Code, Section 102(a), which specifies that copyright protection subsists in original works of authorship, with Locke on p. 101 of Political Essays, defining “copies” as material objects in which a work is fixed.
 Howard B. Abrams, “The Historic Foundation of American Copyright Law: Exploding the Myth of Common Law Copyright,” Wayne Law Review (1982-1983), 1119, 1146-47.
 Political Essays, p. 339.
 Ibid., p. 335.
 Arianne Baggerman, Publishing Policies and Family Strategies: The Fortunes of a Dutch Publishing House in the Late 18th and Early 19th Centuries (Koninklijke Brill, 2013), p. 228.
 Political Essays, p. 335.
 For an unconstrained and comprehensive discussion of the matter, see Tom W. Bell, Intellectual Privilege: Copyright, Common Law, and the Common Good (Mercatus Center, 2014).