One of the cool things about Kant, on Ripstein's reading, is that he is offering a completely different account of the relationship between public right and private right.  As Fiona points out in her draft post, Kant takes freedom to be independence: each person is entitled "to be his or her own master," [4] rather "than the servant of another." [5]  Freedom as independence accounts for the innate private right that each of us has to our own body, and it accounts for why each of us requires a property in things beyond our body, i.e. a private right to land, etc.  But problems of assurance, indeterminacy, and unilateral judgment stand in the way of such legitimate private right to legitimate private property in things beyond our body without the establishment of public powers that can solve these problems of assurance, indeterminacy, and unilateral judgment, in the process paving the way for private right.  In other words, public power is a condition of the extension of private right from our bodies to things and to land.  Notice the subtle but profound shift from Locke and Nozick.  It is not that we have private property, and need the state to protect it; it is that the state (public power) is necessary to establish the conditions of equal individual freedom that are necessary to legitimately acquire rights to private property in things and land.  On this view, you CAN'T have private rights to things and land without the public power of the state.

The chapter 8 argument can be understood as making this point about a specific public power, the power to create, operate, and maintain public roads.  Ripstein is making the case that without public roads maintained by a public authority via public taxation, we cannot have legitimate private property in land.  Private right to land without public roads will violate the conditions of equal individual freedom, hence will be illegitimate.  Putting the point another way, a libertarian account of property fundamentally violates individual liberty -- quite the ironic outcome!  Views about taxes, about when the state can legitimately mandate the cooperation of its citizens, about obligations to the poor, etc., all follow from this fundamental relationship between public and private -- that legitimate public authority is necessary for the the exercise of private right.

Looking forward to tomorrow!