Philo

Volume 12, Issue 1, Spring/Summer 2009

Agnieszka Rostalska, Rafal Urbaniak
Pages 73-87

Swinburne’s Modal Argument for the Existence of a Soul
Formalization and Criticism

This paper evaluates Richard Swinburne’s modal argument for the existence of souls. After a brief presentation of the argument, we describe the main known objection to it, which is called the substitution objection (SO for short), and explain Swinburne’s response to that objection. With this as background, we formalize Swinburne’s argument in a quantified propositional modal language, modifying it so that it is logically valid and contains no tacit assumptions, and we explain why we find Swinburne’s response to SO unsatisfactory. Next, we indicate that, even though SO is quite compelling, a weakening of one of the premises yields a valid argument for the same conclusion which is immune to SO. This version of the argument, however, is epistemically circular.