Self-ownership is a fundamental principle of libertarianism (and voluntaryism); on it is based NaturalLaw and the NonAggressionPrinciple.
There are a few writers that have made the case for objective self-ownership, i.e., that a person has a right (primary, superior) claim on their own body, to control it, use it exclusively, not be harmed, and retain their own production, if peaceful.
Rothbard's case, from Books/TheEthicsOfLiberty is quoted below; Kant's Categorical Imperative is somewhat similar, and Rand also has a derivation of man's rights.
Let us … concentrate on the question of a man's ownership rights to his own body. Here there are two alternatives: either we may lay down a rule that each man should be permitted (i.e. have the right to) the full ownership of his own body, or we may rule that he may not have such complete ownership. If he does, then we have the libertarian natural law for a free society as treated above. But if he does not, if each man is not entitled to full and 100 percent self-ownership, then what does this imply? It implies either one of two conditions: (1) the "communist" one of Universal and Equal Other-ownership, or (2) Partial Ownership of One Group by Another—a system of rule by one class over another. These are the only logical alternatives to a state of 100 percent self-ownership for all.
Let us consider alternative (2); here, one person or group of persons, G, are entitled to own not only themselves but also the remainder of society, R. But, apart from many other problems and difficulties with this kind of system, we cannot here have a universal or natural-law ethic for the human race. We can only have a partial and arbitrary ethic, similar to the view that Hohenzollerns are by nature entitled to rule over non-Hohenzollerns. Indeed, the ethic which states that Class G is entitled to rule over Class R implies that the latter, R, are subhuman beings who do not have a right to participate as full humans in the rights of self-ownership enjoyed by G—but this of course violates the initial assumption that we are carving out an ethic for human beings as such.
What then of alternative (1)? This is the view that, considering individuals A, B, C…, no man is entitled to 100 percent ownership of his own person. Instead, an equal part of the ownership of A's body should be vested in B, C…, and the same should hold true for each of the others. This view, at least, does have the merit of being a universal rule, applying to every person in the society, but it suffers from numerous other difficulties.
In the first place, in practice, if there are more than a very few people in the society, this alternative must break down and reduce to Alternative (2), partial rule by some over others. For it is physically impossible for everyone to keep continual tabs on everyone else, and thereby to exercise his equal share of partial ownership over every other man. In practice, then, this concept of universal and equal other-ownership is Utopian and impossible, and supervision and therefore ownership of others necessarily becomes a specialized activity of a ruling class. Hence, no society which does not have full self-ownership for everyone can enjoy a universal ethic. For this reason alone, 100 percent self-ownership for every man is the only viable political ethic for mankind.
But suppose for the sake of argument that this Utopia could be sustained. What then? In the first place, it is surely absurd to hold that no man is entitled to own himself, and yet to hold that each of these very men is entitled to own a part of all other men! But more than that, would our Utopia be desirable? Can we picture a world in which no man is free to take any action whatsoever without prior approval by everyone else in society? Clearly no man would be able to do anything, and the human race would quickly perish. But if a world of zero or near-zero self-ownership spells death for the human race, then any steps in that direction also contravene the law of what is best for man and his life on earth. And, as we saw above, any ethic where one group is given full ownership of another violates the most elemental rule for any ethic: that it apply to every man. No partial ethics are any better, though they may seem superficially more plausible, than the theory of all power-to-the-Hohenzollerns.
Related: Voluntaryism.