Agnieszka Rostalska

Richard Swinburne (Swinburne and Shoemaker 1984; Swinburne 1986) argues that human beings currently alive have non{bodily immaterial parts called souls. In his main argument in support of this conclusion (modal argument), roughly speaking, from the assumption that it is logically possible that a human being survives the destruction of their body and a few additional premises, he infers the actual existence of souls. After a brief presentation of the argument we describe the main known objection to it, called the substitution objection (SO for short), which is raised by Alston and Smythe (1994), Zimmerman (1991) and Stump and Kretzmann (1996). We then explain Swinburne's response to it (1996). This constitutes a background for the discussion that follows. First, we formalize Swinburne's argument in a quantified propositional modal language so that it is logically valid and contains no tacit assumptions, clearing up some notational issues as we go. Having done that, we explain why we find Swinburne's response unsatisfactory. Next, we indicate that even though SO is quite compelling (albeit for a slightly different reason than the one given previously in the literature), a weakening of one of the premises yields a valid argument for the same conclusion and yet immune to SO. Even this version of the argument, we argue, is epistemically circular.

This paper evaluates Richard Swinburne’s modal argument for the existence of souls. After a brief presentation of the argument, wedescribe 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.

In the Nyāyasūtras (NS), the fundamental text of the Nyāya tradition, testimony is defined as a statement of a reliable speaker (āpta). According to the NS, such a speaker should possess three qualities: competence, honesty and desire to speak. The content of a discourse, including the prescriptions, is also considered reliable due to the status of a given author and the person that communicated it. The Polish philosopher J.M. Bocheński similarly stresses the role of a speaker; he holds that an authoritative source (whose discourse is called testimony) should be competent and truthful. The conditions of trust and superiority also apply. According to Bocheński, being an authority entails a special relation—it has a subject, object and field. Notably, Bocheński develops his own typology of testimony by distinguishing between what he calls epistemic and deontic authority. He asks questions such as: Who can be the subject of an authoritative statement? Which features should the speaker possess? How is authority recognised? Is there a universal or an absolute authority? What is the field of authority? Moreover, which qualities should the listener possess? The Nyāya philosophers, both the ancient ones, like Akṣapāda Gautama, Vātsyāyana, Vācaspati Miśra, and the contemporary scholars of Nyāya, such as B. K. Matilal and J. Ganeri, were also concerned with these issues. The aim of this paper is to discuss the above points in a comparative manner. I will argue that both Bocheński’s and the Nyāya accounts share very similar perspectives and encounter analogous problems.