Cartesian dualist and dualist

Question

I was taught that Cartesian dualists were those who believe strongly that the mind and the body are entirely two separate entities while a dualist believes the same but also believes that the mind and the body interact. Is this true?

Answer 1

It's a bit hard to give a definite answer to your question, but first let's begin by understanding what dualism means.

Dualism is the view that there are two things. (full stop).

But in philosophy, the main place where we hear talk about dualism today is in the mind-body problem so dualism usually means that mind and body are two different things. (see SEP "dualism").

Descartes is one individual well-known for believing mind and body are two different things. And that mind is the source of certainty.

It would be great if we could just stop here and say that "cartesian dualism is the dualism that Descartes had." Unfortunately, cartesian dualism is both:

1. a name for Descartes view
2. a name for a view attributed to Descartes

Some of the things in 2 are not true of what Descartes actually thought. In part this is because cartesian dualism is a very useful foil "Unlike cartesian dualism with mistaken view P, not P."

Looking at the two claims you ask us to address:

Cartesian dualist ... believe strongly that the mind and body are entirely two separate entities

I think it's best to say "Cartesian dualism is the position that mind and body are separate substances."

There's three differences between this and the formulation you suggest:

• "strongly believe" - I don't know what the strongly does here
• "entirely" - this adverb is kind of dangerous here as Descartes does believe they interact somehow which may not make them one thing but certainly complicates the meaning of "entirely"
• "entities" - I think Descartes still sees a person as a single "entity" where that entity is the person which is primarily defined by a mind but does seem somehow connected to a body.

And then for dualism more broadly:

a dualist believes same but also believes that the mind and body interact

This seems problematic because Descartes does believe that they interact - mind controls body and mind receives feedback from the body somehow via the pineal gland.

Simply put dualists (on mind-body) are any views that see mind and body as separable (at least in principle).

It might be easier to understand this by contrast - materialists believe mind is brain, i.e. everything is just body.

Answer 2

Cartesian dualism

Cartesian dualism is interactionist, so a distinction between Cartesian dualism which denies interaction and a dualism that allows it does not apply. It is arguable that Descartes should on his own premises have denied the possibility of interaction but the fact is that he didn't. My own view is that Occasionalism, sketched at the end of the answer, was truer to the logic of Descartes' premises than Descartes himself was.

Cartesian dualism is the view that there is ultimately one substance, God, completely independent and self-explanatory, but that the world God created contains two radically distinct kinds of thing : matter, which is extended and unthinking; and mind, which is thinking and unextended. Descartes, under the proviso of God as the sole ultimate substance, refers to mind and matter (or body) as substances. These are his premises about mind and matter - that they are wholly distinct, with no properties in common.

In the physics and metaphysics of Descartes' day it was prima facie impossible for mind and matter to interact precisely because they had no properties in common. Where, for instance, could matter interact with mind since extensionless mind has no location ?

Mind and body - interaction

Descartes does, however, believe that mind can operate on body. He says in a letter to Arnaud, one of his most acute critics (29 July 1648) :

That the mind, which is incorporeal, can set the body in motion, is something which is shown to us not by any reasoning or comparison with other matters, but by the surest and plainest everyday experience. It is one of those self-evident things which we only make obscure when we try to explain them in terms of other things. (The Philosophical Writings of Descartes, III, The Correspondence, tr. J. Cottingham and others, Cambridge : CUP, 1997 : 358.)

The pineal gland, which figures most famously in The Passions of the Soul (1649), is the locus for mind-body interaction on Descartes's account. In the pineal gland 'animal spirits ... can move the limbs in all the different ways they are capable of being moved' (The Philosophical Writings of Descartes, I, tr. J. Cottingham and others, Cambridge : CUP, 1997 : 341.) Where 'animal spirits' fit in the distinction between mind and matter is not clear. Descartes' descriptions elsewhere are not helpful. In the early Treatise on Man (written c. 1633/4) animal spirits are 'a certain very fine wind, or rather a very lively and pure flame' (The Philosophical Writings of Descartes, I, tr. J. Cottingham and others, Cambridge : CUP, 1997 : 100.) Later reflections do not add substance to metaphor.

Mind/ body - union

Plato

Descartes ... emphatically rejected the Platonistic view of man as a pure mind accidentally united to the body ... Descartes's view of man, as noted above, has actually more in common with Aristotelian-Thomistic dualism than with Platonistic views. The union of the mind and the body is conceived by Descartes as a real and substantial union, on the model of the Aristotelian notion of an individual substance composed of form and matter. But this traditional notion of an immaterial form inhering and working in a material body is notoriously problematic and obscure. Transposed into the framework of Descartes's radical dualism and mechanistic philosophy of nature it appears totally unintelligible. When faced with this difficulty (raised, notably, by [Princess] Elizabeth and Gassendi), Descartes invariably replied that the union of the mind and the body cannot in fact be understood or explained by more clear and distinct ideas, but that it need not be explained at all. The notion we have of this union, according to Descartes, is a « primitive notion », and as such it should be plain to everyone. For it is the notion we have of ourselves as conscious agents, which is familiar from our daily experience and action. (Lilli Alanen, 'Descartes's dualism and the philosophy of mind', Revue de Métaphysique et de Morale, 94e Année, No. 3, (Juillet-Septembre 1989), pp. 391-413 : 395.)

Mind/ body - substantial union

Descartes's main concern, in his later, philosophical work, is with the foundations of knowledge. The human mind is here viewed primarily as an epistemic subject : the focus is on its epistemic capacities and the conditions of secure knowledge. It is in this context that Descartes develops his notion of the mind or the self as an essentially thinking thing, the nature of which is radically different and distinct from that of the extended body. This notion represents what is here considered Descartes's second view or perspective on human nature. As Descartes insists in both the Discourse and the Meditations, the true man, however, is not a purely thinking thing or mind, but a mind closely united to or « intermingled » with a body. This notion of man as a real, or as Descartes also describes it, « substantial » union of the mind and the body, represents Descartes's mature view of man as a conscious and embodied agent. It is a primitive, irreducible notion, covering important features of human experience and action such as sensations, passions and voluntary movements which are not fully intelligible in terms of the notions of extension or thought alone. Viewed from this perspective, man is neither a merely physical nor a purely spiritual being but a third kind of being, with its own distinctive moral nature and experience. This notion of the real or true man, to which Descartes had not paid much attention before the Meditations, can, as he eventually saw and insisted in his correspondence with [Princess] Elizabeth, be understood only through itself. (Lilli Alanen, 'Descartes's dualism and the philosophy of mind', Revue de Métaphysique et de Morale, 94e Année, No. 3, (Juillet-Septembre 1989), pp. 391-413 : 396-7.)

Mind/ body - substantial union : problems

Can this answer be taken seriously ? The mind and the body, as Descartes defines these notions, can be clearly and distinctly conceived only as distinct, when considered separately from each other. But then they cannot without absurdity also be conceived as united, for this would be to conceive them at the same time as two different and one single thing, which, as Descartes admits, is impossible. Although he recognized the difficulty, Descartes did not give up the notion of a real union between the mind and the body, the natures of which are intelligible only when conceived separately from each other. But he drew a distinction between different kinds of knowledge, and insisted that this union belongs to a third primitive notion. The mind-body union, he held, cannot be clearly and distinctly perceived by the pure understanding or the intellect alone, but it is nevertheless clearly perceived by the senses and in daily experience. Can this answer be taken seriously ? The mind and the body, as Descartes defines these notions, can be clearly and distinctly conceived only as distinct, when considered separately from each other. But then they cannot without absurdity also be conceived as united, for this would be to conceive them at the same time as two different and one single thing, which, as Descartes admits, is impossible. Although he recognized the difficulty, Descartes did not give up the notion of a real union between the mind and the body, the natures of which are intelligible only when conceived separately from each other. But he drew a distinction between different kinds of knowledge, and insisted that this union belongs to a third primitive notion. The mind-body union, he held, cannot be clearly and distinctly perceived by the pure understanding or the intellect alone, but it is nevertheless clearly perceived by the senses and in daily experience. Can this answer be taken seriously ? The mind and the body, as Descartes defines these notions, can be clearly and distinctly conceived only as distinct, when considered separately from each other. But then they cannot without absurdity also be conceived as united, for this would be to conceive them at the same time as two different and one single thing, which, as Descartes admits, is impossible.

Although he recognized the difficulty, Descartes did not give up the notion of a real union between the mind and the body, the natures of which are intelligible only when conceived separately from each other. But he drew a distinction between different kinds of knowledge, and insisted that this union belongs to a third primitive notion. The mind-body union, he held, cannot be clearly and distinctly perceived by the pure understanding or the intellect alone, but it is nevertheless clearly perceived by the senses and in daily experience. (Lilli Alanen, 'Descartes's dualism and the philosophy of mind', Revue de Métaphysique et de Morale, 94e Année, No. 3, (Juillet-Septembre 1989), pp. 391-413 : 397.)

Dualism without interactionism

It is, I think, fairly clear that Descartes dealt with the mind/ body relation in a way that is, to say the least, not immediately convincing - at least given his initial premises on the radical division between mind and body. The radically divided become substantially united; and Descartes can give no rationale for this view other than the evidence of the senses and of experience.

The Occasionalist alternative

Arnold Geulincx (1624–69), Nicholas Malebranche (1638-1715) and others came up with an ingenious replacement for Descartes' less than plausible account. Their idea was that mind and body cannnot by their very natures interact. But on the occasion of my having a thought, say the intention to raise my arm, God occasions the appropriate movement of my body. Mental events occasion physical events by divine co-ordination. Occasionalism prefigures in some respects Leibniz's notion of the pre-established harmony.