In this post, I will introduce various forms of the self-ownership thesis, the claim that persons are sole and extensive owners of themselves and the fruits of their labors. In academic philosophy, libertarianism is almost defined by endorsing the self-ownership thesis. It is what unites philosophical left-libertarians and philosophical right-libertarians. But the self-ownership thesis can vary in a number of different ways. Let’s begin with a simple definition (that I take from here):

The Self-Ownership Thesis: Each person enjoys moral ownership of himself or herself (his/her body and mind). 

A corollary of the self-ownership thesis is the misleadingly named “non-aggression axiom.” Consider Murray Rothbard’s words:

The libertarian creed rests upon one central axiom: that no man or group of men may aggress against the person or property of anyone else. “Aggression” is defined as the initiation of the use or threat of physical violence against the person or property of anyone else.

But this definition supposes that persons enjoy moral ownership over their person and property, that is, the fact that persons own themselves provides us and others with reasons to not interfere with their use of their bodies (and property). Rothbard was not making the non-normative claim to body ownership, as this would only amount to the claim that we have power of disposal over ourselves. So it seems that self-ownership is the fundamental principle, not the non-aggression “axiom.”

Self-ownership theses are often coupled with and sometimes taken to imply a principle governing the acquisition of external resources. However, there is substantial and deep philosophical disagreement about what that principle is. The plurality view amongst those who affirm the self-ownership thesis is undoubtedly some right-libertarian principle of initial acquisition and transfer. If a person finds something unowned and mixes her labor with it, it becomes hers and she can transfer it to others on whatever conditions she likes. However, left-libertarians couple a principle of self-ownership with some egalitarian principle of ownership of external property. And geo-libertarians find themselves in between, defending a right-libertarian principle of initial acquisition for everything but land and natural resources and defending a left-libertarian principle of acquisition for land and natural resources (an egalitarian principle of equal distribution of welfare/opportunity).

Self-ownership libertarians (S-OLs)  also disagree on many other important matters. Here are three.

(1) They disagree about the conditions under which you can dispose of your person and property. Some libertarians have held that in virtue of owning your body, you can do whatever you want with it, even selling yourself into slavery (like Walter Block). However, other self-ownership libertarians strenuously deny that a free society would enforce voluntary slavery contracts (like Roderick Long).

(2) They disagree about the extent to which risk can be imposed upon others in ways compatible with their self-ownership. Everything I do with my person and property can potentially impinge and your person and property given some sufficiently small probability. Nozick worried about this at length (see Chapter 4 of Anarchy, State and Utopia), and other libertarians have weighed in, on both the right and left libertarian sides of the question.

(3) Self-ownership theorists disagree about the similarity between ownership rights over one’s body and ownership rights over external property. Some libertarians think that the principles governing the two are distinct but others think they are symmetrical. This matter relates to how one’s conception of personal identity bears on the question of ownership of the body.

So in sum, the self-ownership thesis gives rise to a number of interpretations that vary along at least four dimensions: (i) how to acquire ownership over natural resources, (ii) whether self-ownership permits selling one’s self into slavery and related forms of servitude, (iii) how much risk one can impose on others without violating their bodies or property and (iv) the relationship between personal identity, the body and external resources. These dimensions are interrelated.

At some point I will argue that the counterintuitive implications of the self-ownership thesis are only worth paying (in terms of theoretical costs) if it delivers on other grounds. The most attractive grounds are (i) the self-ownership thesis is simpler than many alternatives and (ii) the self-ownership thesis can yield determinate recommendations. I have not drawn out the counterintuitive implications of the self-ownership principle (the most notorious one is that an easily preventable mass starvation could occur with no injustice done), but we can see from the foregoing that the apparent simplicity and determinacy of the self-ownership principle is likely illusory.