Descarte's Theory Of Substance Dualism

Most famously advocated by René Descartes, substance dualism is the view that minds, which are essentially thinking and consist of mental substance, and bodies, which are necessarily extended and made of material substance, are ontologically separate entities. The material and mental have entirely different natures, so a mind cannot be equivalent to a body. Human beings, therefore, must be mixtures of the two substances. Substance dualists assert that, despite lacking properties in common, mind and body connect through the capacity of each to causally affect the other (Kim 34). While this position may initially appear intuitive and commonsensical, Descartes and subsequent dualists have faced a multitude of challenges concerning mental causation.

In order to account for why A is the cause of X 's death and not Y 's, and for why B is the cause of Y 's death and not X 's, there must be some relation that adequately describes the unique link between A and X and that between B and Y. It is tempting to claim that A is related to X (and not Y) because A and X are part of the same causal chain of events, while the same is true of B 's relation to Y (and not X). However, in addressing the worry about how to pair a cause with its effects one cannot assume the existence of causal relationship! Kim favours a second strategy for explaining causal pairs which emphasizes how objects are situated and spatially relate to one another. The response to the “pairing problem” that results, then, is that gun A and B caused the deaths of their respective victims because each “was fired at a certain distance and in appropriate orientation in relation to the person it hit, but not to the other

Unfortunately, appealing to spatial relations is less helpful when the problem involves an extended body and an unextended mind. Kim introduces a new example: there is one mind and two indistinguishable material bodies, P1 and P2, with the mind having causal impact solely on P1. According to him, if P1 and P2 are inherently indiscernible, then they have identical causal powers. Consequently, discriminating P1 from P2 requires knowledge of the spatial relations that each bears to objects around them. The mind has no spatial location and, unlike a gun, cannot be closer to nor appropriately situated in relation to either P1 or P2. Moreover, given the equivalent “causal capacity” of P1 and P2, it would make little sense to claim for a “causal barrier” to exist between the mind and P2, but not the mind and P1