After having made clear how ownership is possible, Kant goes on to explain how we can come to own things. First he deals with property rights, then with contractual rights, and finally and perhaps most interestingly with how we can acquire rights over persons "in a thing-like fashion." Since his account of property and contractual rights is fairly straightforward, I will say something only about rights over persons "in a thing-like fashion." What Kant has in mind is obvious—at least for the most part. He is talking about marriage, parenthood, and indenture: "A man acquires a wife, a couple acquires children; and a family acquires servants." That these relationships must be seen in terms of "acquisition" is far from obvious to us, but it was obvious to Kant. However, to really understand what Kant means, it is again necessary to understand what was obvious to Kant and is no longer obvious to us, namely, the distinction between possession and ownership. When a man acquires a wife, or "a woman acquires a husband" (that phrase also occurs), he or she does not get ownership of anything, but rather possession of some things but not others. Kant thinks that a person cannot be owned at all. At best, one person may be granted physical possession of the other person. In the case of marriage, the husband and the wife get possession of each other, or more specifically, of each other's sexual organs, and this for enjoyment—not for procreation. Kant believes that because each partner grants the other partner an equal right over himself or herself, there is no violation of the personality of either partner. They both remain free in the most important sense, and neither treats the other merely as a thing. Kant believes, furthermore, that sexual intercourse outside of marriage makes it impossible not to treat the other merely as a thing.
The husband and wife also have the duty to treat each other as beings with moral ends. Similar considerations hold for children. Parents possess them in "a thing-like way." Children have no duties toward their parents. They have only rights to be treated in certain ways. They are always free. Servants, by contrast, are part of a household by contract only. They may be used, but they may not be used up. In other ways, they are more like children. Much of this must certainly seem strange by today's standards. Still, seen in the context of eighteenth-century Prussia, it is really quite "progressive." The woman's function is not clearly subordinated to that of the man. There is mutual recognition between them. The wife's role is not exhausted by procreation. She governs the household together with the husband, and while her role is restricted to the household, it is of perhaps greater importance than any public role the husband may play.
(Manfred Kuehn, Kant: A Biography [Cambridge: Cambridge University Press, 2001], 398-9 [italics in original; endnote omitted])
Keith Burgess-Jackson, J.D., Ph.D. 