Abstract

Special relativity inclines most contemporary interpreters (DiSalle, Maudlin, Penrose, Sider, Wheeler) away from the Thomistic three-dimensional, substance ontology. Most interpreters say space and time serve only as hermeneutics for accessing the deeper ontological foundation, four-dimensional spacetime. Unfortunately, this reigning narrative seems to replace the conventions of measuring rods and clocks with an even greater convention. Noticeably absent in the literature is a Thomistic interpretation of special relativity. Some Thomistic authors (Feser, Kiley, McLaughlin, Moreno) defend aspects of Aquinas’ metaphysics on the periphery of special relativity, and suggest misgivings about four-dimensionalism. But none have attempted to demonstrate the viability of a three-dimensional alternative. This paper attempts to do just that, to provide a three-dimensional, Thomistic interpretation of special relativistic phenomenon—specifically, length contraction and time dilation. Behind this phenomenon, I argue, is the ordinary physical structure of clocks and the fact that every Aristotelian motion involves multiple true velocities.