Final answer:
Arguments against substance dualism often focus on the supposed interaction between mind and body, challenging how an immaterial mind can affect a physical body within the framework of the causal closure of the physical world.
Step-by-step explanation:
An argument against substance dualism could point to the difficulties in explaining the interaction between the mind and body if they are fundamentally different substances. Dualism posits the existence of both physical (material) and non-physical (spiritual) substances, which René Descartes famously supported by distinguishing between the 'res cogitans' (mind) and 'res extensa' (body).
One criticism is based on the idea of the causal closure of the physical, which suggests that if the physical world is causally closed, then an immaterial mind cannot affect the physical body. However, one must also consider criticisms of dualism that question how these two distinct substances interact, as this seems to violate the conservation of energy and the principle of simplicity (Ockam’s Razor).
Dualists may respond by suggesting non-physical entities follow different metaphysical laws, or arguing that despite the lack of physical properties, the mind can bring about change in the physical body through mechanisms not yet fully understood. Critics of dualism propose that the evidence for mind-body interaction can be explained solely through physical brain actions, questioning the need for a non-physical substance.