Tommaso Soriani

In a recent article, Montminy and Russo (M&R) (2024) defend a perdurantist solution to forward- and backward-looking cases of Johnston’s Personite Problem (2016, 2017), specifically addressing the issue of compensation for personites—non-maximal fusions of Rinterrelated person-stages that overlap with a perduring person, the maximal fusion of those stages—by appealing to a revised understanding of temporal properties within a perdurantist framework. In this paper we address an overlooked problem with M&R’s account: when applied consistently, it yields a counterintuitive grounding overdetermination (overgrounding) of temporal properties. The problem becomes especially vivid in fission scenarios that are followed by fusion.

In a recent article, Montminy and Russo (M&R) (2024) defend a perdurantist solution to forward- and backward-looking cases of Johnston’s Personite Problem (2016, 2017) specifically addressing the issue of compensation for personites—non-maximal fusions of R-interrelated person-stages that overlap with a perduring person, the maximal fusion of those stages—by appealing to a revised understanding of temporal properties within a perdurantist framework. In this paper we address an overlooked problem with M&R’s account: when applied consistently, it yields a counterintuitive grounding overdetermination (overgrounding) of temporal properties. The problem becomes especially vivid in fission scenarios that are followed by fusion.

According to Mark Johnston’s Personite Problem, Perdurantism—the view that persons are maximal fusions of person-stages—should be rejected, as it fails to account for the moral status of non-maximal fusions that overlap a person ( personites ). His Duplication Argument claims that personites have persons as duplicates in other metaphysically possible worlds. Since duplicates share all intrinsic descriptive properties, they must share normative ones, including moral status. I challenge this by accepting Johnston’s duplication claim but rejecting its moral conclusion. Perdurantists can respond by adopting Moral Contingentism: the view that pure moral laws are not metaphysically necessary but only normatively necessary, hence metaphysically contingent. These perdurantists can maintain metaphysically possible worlds where personites have person-duplicates, while holding these worlds normatively impossible (i.e., countermoral ). Countermoral worlds—differing in their pure moral laws and thus how they ground moral status—cannot confer moral status on personites through duplication in normatively possible worlds, including the actual one.

According to Mark Johnston’s Personite Problem, Perdurantism—the view that persons are maximal fusions of person-stages—should be rejected, as it fails to account for the moral status of non-maximal fusions that overlap a person (personites). His Duplication Argument claims that personites have persons as duplicates in other metaphysically possible worlds. Since duplicates share all intrinsic descriptive properties, they must share normative ones, including moral status. I challenge this by accepting Johnston’s duplication claim but rejecting its moral conclusion. Perdurantists can respond by adopting Moral Contingentism: the view that pure moral laws are not metaphysically necessary but only normatively necessary, hence metaphysically contingent. These perdurantists can maintain metaphysically possible worlds where personites have person-duplicates, while holding these worlds normatively impossible (i.e., countermoral). Countermoral worlds—differing in their pure moral laws and thus how they ground moral status—cannot confer moral status on personites through duplication in normatively possible worlds, including the actual one.

According to Perdurantism, persons are identical to maximal aggregates of appropriately interrelated temporal parts. Within the Perdurantist framework, an epistemic concern arises, targeting the perduring persons’ belief that they are persons, suggesting that, ultimately, they are not in a position to know that they are persons as opposed to temporal parts. Despite the consideration it has received over the years, this concern has not yet been converted into a full-fledged objection. This paper aims to address this gap by exploring the possibility of formulating a coherent Epistemic Objection against Perdurantism. We shall examine several epistemological principles around which such an objection might be built, arguing that none of them, in the end, allows a plausible formulation of the objection. As a result, we shall conclude that the burden of proving that in a Perdurantist setting persons are not in a position to know that they are persons rests with the objectors.

According to Perdurantism, persons are identical to maximal aggregates of appropriately interrelated temporal parts. Within the Perdurantist framework, an epistemic concern arises, targeting the perduring persons’ belief that they are persons, suggesting that, ultimately, they are not in a position to know that they are persons as opposed to temporal parts. Despite the consideration it has received over the years, this concern has not yet been converted into a full-fledged objection. This paper aims to address this gap by exploring the possibility of formulating a coherent Epistemic Objection against Perdurantism. We shall examine several epistemological principles around which such an objection might be built, arguing that none of them, in the end, allows a plausible formulation of the objection. As a result, we shall conclude that the burden of proving that in a Perdurantist setting persons are not in a position to know that they are persons rests with the objectors.