Explain the doctrine of Cartesian dualism and examine critically arguments in favour of it.

The Doctrine of Cartesian Dualism

At the heart of Cartesian Dualism lies the concept of ‘substance’. Descartes defined a substance as something that exists independently and requires nothing else for its existence. He argued that mind and body meet this criterion, but are radically different. The mind, or ‘res cogitans’ (thinking thing), is non-extended, indivisible, and conscious. The body, or ‘res extensa’ (extended thing), is spatially extended, divisible, and operates according to mechanical laws. A crucial aspect of Descartes’ theory is the assertion that these two substances causally interact, primarily through the pineal gland in the brain.

Arguments in Favour of Cartesian Dualism

1. The Argument from Doubt

Descartes’ famous method of doubt, as outlined in his *Meditations on First Philosophy* (1641), forms a cornerstone of his dualistic argument. He systematically doubted everything he could possibly doubt, ultimately arriving at the certainty of his own existence as a thinking being ("Cogito, ergo sum" – I think, therefore I am). He argued that because he could conceive of his mind existing without his body, and vice versa, they must be distinct substances. The very possibility of doubting the existence of the body, while affirming the existence of the mind, demonstrates their fundamental difference.

2. The Argument from Divisibility

This argument centers on the differing properties of mind and body. The body, being a material object, is divisible – it can be broken down into smaller and smaller parts. The mind, however, is indivisible; it is a unified, singular consciousness. Descartes reasoned that if something is divisible, it must be material, and if something is indivisible, it must be immaterial. Therefore, the mind cannot be material and must be a distinct, non-physical substance.

3. The Argument from Intentionality

Intentionality refers to the ‘aboutness’ of mental states – the fact that our thoughts, beliefs, and desires are *directed* towards objects or states of affairs. For example, I can think *about* an apple, or desire *to go* to the beach. Descartes argued that material objects lack this inherent intentionality. A physical object simply *is*; it doesn’t represent or refer to anything else. Because the mind possesses intentionality, and material objects do not, the mind must be fundamentally different from matter.

4. The Argument from Subjective Experience (Qualia)

This argument, more prominent in contemporary discussions, suggests that subjective experiences – the ‘what it’s like’ aspect of consciousness (known as qualia) – are impossible to reduce to physical descriptions. The redness of red, the pain of a headache, the taste of chocolate – these are qualitative experiences that seem fundamentally different from any objective, physical measurement. Dualists argue that this irreducibility points to a non-physical aspect of the mind.

Critical Examination of the Arguments

1. Critique of the Argument from Doubt

Critics argue that Descartes’ ability to conceive of mind and body as separate does not necessarily imply their actual separation. Just because we can *imagine* something doesn’t mean it’s real. Furthermore, the argument relies on a questionable assumption about the relationship between conceivability and possibility. It’s possible to conceive of many things that are logically impossible.

2. Critique of the Argument from Divisibility

Modern neuroscience challenges the notion that the mind is indivisible. Brain damage can lead to specific cognitive deficits, suggesting that mental functions are localized and can be disrupted by physical changes. This implies that the mind is, in some way, dependent on and potentially divisible *with* the brain. Furthermore, the concept of a ‘distributed’ mind, where cognitive processes are spread across multiple brain regions, undermines the idea of a unified, indivisible consciousness.

3. Critique of the Argument from Intentionality

Functionalism, a prominent theory in the philosophy of mind, offers a counter-argument. Functionalists argue that intentionality can be explained in terms of the functional role of mental states – their causal relations to inputs, outputs, and other mental states. They suggest that intentionality is not an inherent property of consciousness, but rather a property of systems that *process* information in a certain way. This allows for the possibility of artificial intelligence exhibiting intentionality, even without a non-physical mind.

4. Critique of the Argument from Qualia

Physicalists attempt to explain qualia in terms of brain states and neural processes. Eliminative materialism goes further, arguing that qualia are illusory – that our subjective experiences are simply misinterpretations of underlying physical processes. While these explanations are controversial, they demonstrate that qualia are not necessarily incompatible with a physicalist worldview.