Lockean proviso

The term "Lockean proviso" was coined in 1974 by an American libertarian to describe an interpretation of John Locke's labor theory of property, which states that whilst individuals have a right to homestead private property from nature by working on it, they can do so only if "there was still enough, and as good left; and more than the yet unprovided could use".

Preliminary wording central to Locke's concept of property is set out in Chapter V, paragraph 27 of his Second Treatise of Government:

Though the earth, and all inferior creatures, be common to all men, yet every man has a property in his own person: this no body has any right to but himself. The labour of his body, and the work of his hands, we may say, are properly his. Whatsoever then he removes out of the state that nature hath provided, and left it in, he hath mixed his labour with, and joined to it something that is his own, and thereby makes it his property. It being by him removed from the common state nature hath placed it in, it hath by this labour something annexed to it, that excludes the common right of other men: for this labour being the unquestionable property of the labourer, no man but he can have a right to what that is once joined to, at least where there is enough, and as good, left in common for others.

— John Locke, Second Treatise of Government, Chapter V, paragraph 27

His proviso is then formulated as follows:

Nor was this appropriation of any parcel of land, by improving it, any prejudice to any other man, since there was still enough and as good left, and more than the yet unprovided could use. So that, in effect, there was never the less left for others because of his enclosure for himself. For he that leaves as much as another can make use of, does as good as take nothing at all. Nobody could think himself injured by the drinking of another man, though he took a good draught, who had a whole river of the same water left him to quench his thirst. And the case of land and water, where there is enough of both, is perfectly the same.

— John Locke, Second Treatise of Government, Chapter V, paragraph 33

The phrase "Lockean proviso" was coined in 1974 by American libertarian political philosopher Robert Nozick in Anarchy, State, and Utopia. It is based on the ideas elaborated by Locke in his Second Treatise of Government, namely that self-ownership allows a person the freedom to mix his or her labor with natural resources, converting common property into private property. Locke concludes that people need to be able to protect the resources they are using to live on their property and that this is a natural right. Nozick used this idea to form his Lockean proviso which governs the initial acquisition of property in a society, but in order for his ideas of ownership of property to get off the ground and be cogent he devised the criterion to determine what makes property acquisition just, which is the proviso. The proviso says that although every appropriation of property is a diminution of another's rights to it, it is acceptable as long as it does not make anyone worse off than they would have been without any private property.