R&D are surely correct in saying that there is no
common stock of goods that everyone must equally regard as “wealth.” Property and wealth are not beings in rerum natura — that is, things that exist “out there” independently and apart of human cognition and effort.
But why insist that “the right to property is a function of the right to action” and even that “it is not objects per se that individuals need to have property rights to”? (Ch. 5)
Traditionally, we would say that people have property rights indeed over objects, yet freedom to act, rather than property rights to act.
Perhaps R&D want to emphasize that objects ought to satisfy some human ends if they are to be counted as wealth, either directly as consumer goods or indirectly as capital. Moreover, goods of the highest order that are simply found in nature and appropriated are not particularly well-suited for consumption; they must be transformed first through labor. Plus, what is “capital” depends on each individual’s mind: the same “thing” can be one type of good to one person, another type to a different person, and an entirely useless thing to yet a third; it is precisely these differences that generate entrepreneurial competition for capital. We also need to have an economy, as a systematic way of producing new goods when existing goods depreciate. We also want this economy to feature creative advance, that is, improvement in human productive capacities, and we want for our economy to become larger through integration of new lands into global social cooperation and for its division of labor to intensify, as in becomes more minute.
Even is they want to stress the unity of thing and act, I think it is a confusion to refer to property rights in actions.
Lastly, I don’t think that “two-substance dualism” can be proven false just from the premise that “the choices, judgments, or intentions of human action are ultimately realized in terms of material and physical realities in space and time.” Dualism may be true even if soul and body are intimately intertwined in a psychosomatic unity.