MANCEPT panel “The disputes on human agency: implications for politics and law“. September 7-10, 2021
The traditional concept of a person was that of an individual substance of a rational nature – a definition proposed by Boethius and developed by Thomas Aquinas. List and Pettit called this the intrincisist conception and contrasted it with a more modern performative conception of personhood. On the performative conception, the focus is not on a substantial definition of personhood, but on what a person can do, i.e. perform the function of tracking rights and obligations over time. This conception arose in legal thinking and was developed by Locke and Hobbes. The aim of this contribution is to develop a metaphysics of personhood that does justice to both these conceptions.
The proposal is inspired by, though distinct from, Lindahl’s distinction between a person’s ability space and a person’s liberty space. A person’s ability space refers to the set of alternative states of affairs that a person can manifest or actualize, based on a standard libertarian principle of alternative possibilities. This is taken here as an irreducible feature of reality that is present in persons. It implies that persons are a point of irreducible contingency at which things are determined to be one way rather than another way.
At the same time, and based on that, each person possesses a liberty space as the set of alternative states of affairs that is recognized by other persons as belonging to that other person. Certain elements of one’s ability space are not a member of one’s liberty space, as in the case of petty thievery. Certain elements of one’s liberty space are not a member of one’s ability space, as in the case of a president sending out bomber planes while being unable to fly them himself.
This proposal is close enough to the performative conception of personhood to easily allow for legal personhood, i.e. as a bundle of rights and obligations that persists over time during which various natural persons can perform these functions. At the same time, it follows that only natural persons with genuine metaphysical alternative possibilities can perform these functions, implying the primordiality of a more intrincisist conception of personhood.Alternative possibilities are in that sense the defining feature of personhood as a point of contingency at which reality is determined to be one way rather than another. Persons and their contingent actions are then part of the explanans of reality, not part of the explanandum. This raises the metaphysical stakes for both sides of the debate about naturalism and personhood. Denying persons their place at the origin of explanatory chains would amount to a petitio principii, but endorsing it would bring them very close to that of a creator God in whose image they were allegedly made and who determines all of reality to be one way rather than another. On the other hand, doing so would open a way to explore the close connection between personhood and (divine or Westphalian) sovereignty.