Descartes Substance Dualism

Descartes presents his idea of dualism with two substances. The first of these substances is res extensa, these are all of the physical entities in the material world including our body. The second substance is res cogitans and these are our mental states. Together, these two substances form Descartes substance dualism theory. Descartes begins his defence of this theory by presenting the indivisibility argument, which follows like this, my mental states and mind cannot be divided in the way a physical object can and physical objects can be divided, so for X (the body) to be identical to Y (the mind) they must have identical essential properties, and they do not. This would therefore mean that as the mind is indivisible and the physical is,

This means that the mind may be functionally divisible, but they are not spatially divisible as the body may be i.e. the mind can be broken down into functions but these functions do not have locations because they are not spatially located at all. However, Descartes argument is slightly questionable since he assumes that the mind is a substance and can exist independently of the body, meaning he assumes the conceivability argument, which itself has issues with it. If minds were not substances and were just properties of the brain then it would hardly be unbelievable that the mind is indivisible, but then the mind would be physical. This is because that only that that is spatial can technically be divisible and that which retains indivisible non-spatial properties, like belonging to a religion, it is a physical property but it is indivisible.

Descartes substance dualism is food for thought, but so is property dualism. This theory is historically associated with the philosopher Baruch Spinoza. The theory is that whilst there may only be one substance, both mental and the physical are different and independent kinds of properties of that one substance, so can manifest in the same object. Spinoza believed that this substance was