Fabio Patrone

Derek Parfit played a crucial role in the XX century philosophical debate. His masterpiece, Reasons and Persons, has been highly influential both in moral philosophy, and personal identity. It is hard to overlook the fact that Parfit’s ideas gave the main contribution to the contemporary philosophy of persons. He reformulates a debate stuck in the classical contraposition between psychological and physical criteria of personal identity, by introducing his most famous idea: identity doesn’t matter in survival. This thesis, and its moral implications, has been a challenge for everyone tackling the issues related to persons and normative moral philosophy.

Pixelism is the combination of three metaphysical thesis, namely a radical form of exdurantism, mereological nihilism and counterpart theory. Pixelism is a theory that evaluates all the metaphysical phenomena of persistence, composition and modality in a homogeneous and consistent manner. In a pixel world, there is no identity over time and over possible worlds and nothing persists over more than an instant or a world. Entities can be univocally identified by a five-coordinates system (the three spatial dimensions, the temporal one and the possible worlds), and their relation is a counterpart relation both in different worlds and at different times or different regions of space. In this paper I will provide two models for pixelism: the first one takes pixels to be hypercubes, i. e. four-dimensional cubes, the acceptance of which is conditional on the acceptance of extended simples. The second one considers pixels as points in a four-dimensional space.

Derek Parfit’s thesis that identity doesn’t matter in survival has been extensively discussed except for its metaphysical robustness. How can we justify the abandonment of identity in the way Parfit suggests? My argument is the following. Those who want to endorse the thesis that identity doesn’t matter (and, therefore, abandon identity across time) should adopt exdurantism, i.e. a metaphysics according to which the world is composed by temporal parts each existing at a time and according to which there is nothing as a numerically same entity which exists at different times. I show that the metaphysics behind Parfit’s theory is neither compatible with endurantism, according to which object persists by being wholly present at different times, nor with perdurantism, according to which entities are aggregates of temporal and spatial parts.