Among the necessary requirements that must be satisfied before I can legitimately claim an external object as my private property is the exercise of my will. No one can compel me to accept as my property something that I didn’t previously own; I must will this to be so, according to Kant.

Starting with this role of the will in acquiring property, Kant called attention to a very interesting issue. By my act of will, and mine alone, I can morally obligate everyone else in society (indeed, in the entire world) to respect my decisions regarding my property. And this moral right is also an enforceable moral claim, one that permits me to use physical force against those who attempt to violate my property rights.

So how is it that my singular will can obligate everyone else to follow my desires regarding my property? Kant regarded this question as among the most the most important and difficult problems in political philosophy. As I explained in an earlier essay, Kant argued that the right to use force in defense of a (juridical) right is an essential element in the original right itself. It is not as if the right to use defensive force is somehow tacked on to the original right and justified with a separate argument. Rather, our right to use force in defense of our rights is integral to what we mean by “a right” in the first place. Thus to claim a right to use and dispose of our property is simultaneously to claim a right to use force against those who attempt to violate this moral claim.

From this inseparable relationship between a rights‐​claim and the legitimate power to enforce that claim, it follows that a right that can never be enforced by impartial means lacks a key ingredient of the concept. A just society demands more than that legitimate claims about property rights be widely accepted; a just society also requires a reasonably reliable mechanism that can enforce our rights. It is not enough for me to say “I have a right to X” for justice to be realized. Justice also requires that I and others be able to enforce our rights against violators. I may claim all the rights I like, and those claims may be perfectly legitimate, but if criminals live in a society where they can steal with impunity or murder with no fear of punishment, then, in Kant’s view, that society would not qualify as a just society. Here we have the substance of Kant’s point that property rights in a state of nature would be provisional and that only in a civil society can those selfsame rights qualify as juridical. In other words, since a state of nature without government would lack objective laws, all rights in a state of nature, though theoretically applicable, would lack an impartial mechanism of enforcement and would therefore lack an essential feature of what we mean by “a right.”

Moreover, as Kant understood his own Categorical Imperative, I may claim rights for myself only if I recognize the equal rights of everyone else. And since to claim a right for myself is simultaneously to claim my right to use force against anyone who seeks to violate that right, this entails that I must acknowledge the equal right of others to use force against me should I attempt to violate their rights. Rights, in short, require reciprocity by all members of a society, which includes the understanding that others may legitimately use force against me if I attempt to violate their rights. But the impartial enforcement of rights is a mere will-o’-the-wisp in a state of nature that lacks the rule of law, so others may coerce me to become subject to a state in which we find the rule of law. This subjection to an existing government, even without my “empirical” consent, is a dictate of practical reason. It is logically demanded of me because unless I submit to a government that protects the rights of everyone, I cannot claim any rights for myself. It may therefore be said that in asserting my right to freedom, I have simultaneously agreed, if only in a theoretical sense, to obey the decrees of a government whose job it is to protect the rights of every person within its jurisdiction. (Kant’s position on this matter, it should be noted, is not a theory of tacit consent, but it may be characterized as a theory of implied consent, if we interpret “implied” in a logical sense.)

I’m afraid this is the best I can do, for good or ill, in attempting to summarize Kant’s basic justification of government, and why his theoretical version of the social contract does not require the real consent of individuals, who should be compelled to become members of a political society. But there is an obvious problem here when we consider Kant’s claim that we are morally obligated to obey every law of every government, including the unjust laws of tyrannical governments. Even if we agree that people may properly be compelled to obey a rule of law, as enforced by a just government, when laws are designed to protect the individual’s right to freedom, it does not necessarily follow that we are similarly obligated to obey the unjust laws of a tyrannical government.