The theory of property defended by John Locke in chapter 5 of his Second Treatise of Government remains the most discussed in the history of its subject. Supporters and detractors alike appear for the most part to agree that Locke's theory at least requires careful consideration. The central thesis of that theory – that labor is the original source of exclusive property rights – has proved to be enormously influential and durable. Indeed, it is usually difficult for contemporary readers of Locke (who approach the text without firm theoretical predilections) not to conclude that Locke's central thesis is simply true.

Locke's explanation of why labor grounds property, however, has proved far less persuasive to contemporary audiences. His initial claim appears to be that in laboring we mix what we own (our person and its labor) with what we do not own (“nature”), thereby making it wrong for others to take or use the product of our labor, that product “including” as it does the labor that is ours (II,27). Locke's critics have not treated this argument kindly, suggesting that the principal inference in the argument is a non sequitur, that the argument as a whole involves a reasonably basic category mistake, or that Locke's assertions, when taken literally, are simply unintelligible.

Locke's most recent interpreters, however, have sought to do better for Locke than he (initially) appears to do for himself, explaining why labor grounds property for Locke by placing his principal discussion of these matters (in Chapter 5 of the Second Treatise) in a more illuminating context.