Mixing and transforming
My opening commentary on the rest of the sequence - see the beginning here - completed, I turn finally to (3), labour-mixing itself, as a basis for claims of private ownership. I shall examine it after one last preliminary, a brief answer to the question why I see it as meriting attention. Its importance may well be doubted. After all, this ideal story of acquisition through labour, from an original position of non-ownership of external things, bears a rather distant relation to the real history of the world; of private property in particular.20 Why bother with the discussion of such a mythical route to economic-distributional patterns whose real genesis has plainly been different?
My answer is that, first, the issue of what is a normatively adequate genesis of property titles is a crucial one, irrespective of the actual history of actual property. For, as Hillel Steiner has put this point, 'it is a necessary truth that no object can be made from nothing, and hence that all titles to manufactured or freely transferred objects must derive from titles to natural and previously unowned objects.' Consequently, for anything at all ever to be owned, it, or the constituents of it, must have a first owner; and we may reasonably enquire just what it is that gives this person, or group, rights over the thing. If nothing does, all claims subsequently derived from the initial (de facto) title are put in question.21 'Original position' or 'state of nature' constructions of the process of appropriation are a methodological device for fastening upon such normative origins; a convenient way of focusing on the foundational conceptual moment by artificially treating it as a chronological one. They are a selective abstraction.
Second, the selection of precisely labour-mixing for scrutiny in this context, notwithstanding the fact that it is scarcely possible any longer with unowned resources, is motivated by my belief that the principle encapsulates, nevertheless, a normative idea of continuing currency and some apparent force. We have seen this idea formulated once already. It was expressed also by John Stuart Mill: 'Private property, in every defence made of it, is supposed to mean, the guarantee to individuals of the fruits of their own labour...'22 My interest here happens to be in anti-egalitarian usages of the idea. But it will not have failed to occur to readers that entitlement to the fruits of one's labour also has a socialist pedigree, and that the (or at least one) Marxist concept of exploitation depends on it: the concept, namely, that workers are exploited when, and in that, a portion of the value they create is appropriated by their capitalist employers. I examine the labour-mixing argument with a view also to assessing some cognate ideas.
In the Second Treatise, then, John Locke offers several labour-based justifications for acquisition. It is a moot point whether those other than labour-mixing as such were intended or understood by him as wholly distinct from it. That labour costs effort, for example, or that it makes things more valuable to people - were these meant as separate, additional justifications, or does the labour-mixing argument itself ride on them? Later, I consider the possibility that it does. But if it does, it is important to recognize this, for it has significant consequences. We need, first, to know how the argument fares on its own.
Locke in any case, in making that argument, repeatedly uses a style of formulation whose force is different from asserting that labour is effortful, or value-creating; or of any other particular quality. As the passage earlier cited says, what a man removes from its natural state he has mixed his labour with, 'and joined to it something that is his own, and thereby makes it his property' (my emphasis). Locke expresses this thought twice more in the same paragraph: '[the object] hath by this labour something annexed to it that excludes the common right of other men'; and 'this labour being the unquestionable property of the labourer, no man but he can have a right to what that is once joined to...' Shortly afterwards, he speaks also of man 'lay[ing] out something upon it [the earth] that was his own, his labour'; 'annex[ing] to it something that was his property, which another had no title to, nor could without injury take from him.'23
That labouring on something entitles you to own it turns, in all these formulations, on what you have mixed into the virgin matter being, not your labour, but simply yours. It is that it is yours and mixed, not that it was hard or value-enhancing, that counts here. The inference from mixture to entitlement would work for any of your property you mixed - except, only, for one circumstance. For, though Locke does not make this explicit, it is critical to the inference that the mixing is irrevocable. What is joined cannot be disjoined. Otherwise, someone could just extricate the mixed-in stuff from what it was mixed into, and make off with the latter themselves, having returned to you what was yours; 'without injury'. The burden of the argument is that they cannot deprive you of the hitherto unowned matter without depriving you simultaneously of what you own.24
 Cf. Karl Marx, Capital, Volume I, Chapter 26.
 Hillel Steiner, 'Justice and Entitlement', Ethics, 87 (1977), p. 151. Cf. Cohen I, p. 119; and F. A. Harper, 'Property and its Primary Form', and George I. Mavrodes, 'Property', in Blumenfeld, pp. 11-12 and 185 respectively.
 John Stuart Mill, Principles of Political Economy, Book II, Chapter I, sec. 3.
 Two Treatises, II, secs. 27 and 32.
 See, for contemporary formulations of the point, Murray Rothbard, 'Justice and Property Rights', in Blumenfeld, p. 113; and Hillel Steiner, 'Slavery, Socialism, and Private Property', in J. R. Pennock and J. W. Chapman (eds.), Nomos XXII: Property (New York: NYUP, 1980), pp. 262-3 n. 15; and cf. also his 'Capitalism, Justice and Equal Starts', Social Philosophy & Policy, 5 (1987), p. 54.
(Part 6 is here.)