8 Res Cogitans and Dualism. The immateriality of the soul. Doubt I can doubt whether I have a body, but I cannot doubt that I am or exist. This argument, though, is invalid (see Arnauld’s objection CSM II : 139).
I can doubt whether I have a body, but I cannot doubt that I am or exist.
This argument, though, is invalid (see Arnauld’s objection CSM II: 139).
From the fact that I doubt that something possesses a given property it doesn’t follow that this very thing lacks it.
Thus from the fact that I can doubt about me having a body and that I cannot doubt that I am thinking it does not follow that the soul is immaterial.
From “I doubt p & I cannot doubt q” it doesn’t follow that q is not p.
E.g.: From “I doubt that 2+2=4 & I cannot doubt that 3+1=4” it doesn’t follow that 2+2 is not 3+1.
I can clearly and distinctly perceive the mind apart from body (see fifth meditation).
Arnauld suggested that this argument is similar to the doubt argument (see CSM II: 142).
One can clearly and distinctly perceive that a triangle has a right angle and yet not clearly and distinctly perceive that it has the Pythagorean property. But even God could not create a right-angled triangle which lacks it.
Descartes’ reply consists in arguing that neither the triangle nor its property can be seen as a complete thing, while the mind and the body must.
Since in my thinking I can conceive the mind/soul to subsist independently of physical properties it is perfectly conceivable that God created my thinking substance without creating the physical ones.
Hence the physical attributes do not belong to the essence of the soul/mind.
There is a great difference between the mind and the body inasmuch as the body is by its very nature always divisible while the mind is utterly indivisible. For when I consider the mind, or myself in so far as I am merely a thinking thing, I am unable to distinguish any part within myself; I understand myself to be something quite single and complete. Although the whole mind seems to be united to the whole body I recognise that if a foot or an arm or any other part of the body is cut off nothing has thereby been taken away from the mind. (Sixth Meditation;CMS II: 59)
Descartes circumvents this problem in concentrating on pure thought (he recognises that some mental activity such as imagination and sense-perception depends on the brain), e.g. thoughts of abstract objects.
Even if the body is destroyed, the mind or soul would not be harmed: it would merely leave the body. The soul/mind is immortal.
This doctrine, though, has already been established a priori: it does not rest on the divisibility argument.
Prem. 1: If I can clearly and distinctly understand A apart from B and B apart from A, then God could have created one without the other, and A cannot depend on B for its existence, or B on A.
Prem. 2: I can clearly and distinctly understand myself as a thinking thing apart from body, and a body as an extended thing apart from thought.
PreliminaryConclusion: God could have created my mind in such a way that it does not depend on any body.
Prem. 3: God could have created my mind in such a way that it does not depend on any body.
Prem. 4: If A could have been created to be independent of B, A can exist when B no longer exists.
Prem. 5: When I am dead, my body (as such) will no longer exist.
Conclusion: I can exist when my body is dead.
(Cf. Dan Scotus) Some predicates can be conceived apart from one another and, yet, they cannot exist apart from one another:
E.g.: divine justice and divine mercy; it is impossible for God to be just and not merciful as it is impossible for Him to be merciful without also being just.
For it to be the case that we can understand two things distinctly and separately, they must really be entities in their own right.
The ability to employ imagination suggests the presence of the body. If there can be thought without imagination, as Descartes suggests, there can be thought without a body.
Imagination, like perception, is not essential to a subject. Thus, if the souls is immortal it does not involve imagination and perception; it merely requires intellectual understanding.
To prove that the mind and the body are
1. real subjects
2. numerically distinct entities
3. can exist without the other
a = b (F) (Fa Fb)
If a and b are identical then each property of a must also be a property of b and vice versa.
(F) (Fa Fb) a = b
This is the converse of Leibniz’s law and states that if every property of a is also a property of b and vice versa (i.e. there is no discernible difference between them), then a and b are identical.
If a and b have all properties in common, then a and b are identical.
If MIND and BODY have all properties in common, then MIND = BODY
If MIND and BODY differ in some property, then MINDBODY
x and y are distinct insofar as x and/or y can be conceived/understood without each other.
[F]or establishing a real distinction it is sufficient that two things can be understood as ‘complete’ and that each one can be understood apart from the other. (Reply to Arnauld; Fourth Set of Replies; CSM II: 156)
Descartes’ criterion of distinctiveness is epistemological.
Yet, since clear and distinct ideas must reflect the true nature of things, distinct ideas reflect distinct substances.
How can ideas be distinct and thus represent different substances?
Descartes draws a comparison between mental intuition (perception) and seeing with the eyes
Indeed there are very many people who in their entire lives never perceive anything with sufficient accuracy to enable them to make a judgement about it with certainty. A perception which can serve as the basis for a certain and indubitable judgement needs to be not merely clear but also distinct. I call a perception ‘clear’ when it is present and accessible to the attentivemind—just as we say that we see something clearly when it is present to the eye’s gaze and stimulate it with sufficient degree of strength and accessibility. I call a perception ‘distinct’ if, as well as being clear, it is so sharply separated from all other perceptions that it contains within itself only what is clear. (Principles of Philosophy 45; CSM I: 207-8)
Descartes’ account of knowledge is thus based on direct mental apprehension.
Mental intuition goes proxy for mental acquaintance/grasping.
In discussing the “action of the intellect by mean of which we are able to arrive to the knowledge of things with no fear of mistake” (Rules for the Direction of the Mind; CSM I: 14), Descartes recognizes two intellectual actions: intuition and deduction.
By ‘intuition’ I do not mean the fluctuating testimony of the senses or the deceptive judgement of the imagination as it botches things together, but the conception of a clear and attentive mind, which is so easy and distinct that there can be no room for doubt about what we are understanding. Alternatively, and this comes to the same thing, intuition is the indubitable conception of a clear and attentive mind which proceeds solely from the light of reason. … Thus everyone can mentally intuit that he exists, that he is thinking, that a triangle is bounded by just three lines, and a sphere by a single surface, and the like. (Rules for the Direction of the Mind; CSM I: 14)
They have been created by God and God makes us to recognize them (following Descartes’ method of doubt). God could have created other necessary truths; even the more basic laws of logic could have been different if God wished so.
All eternal/necessary truth depend on God’s will.
That is, one cannot infer from his subjective state of certainty or uncertainty concerning a given fact, to the objective certainty or uncertainty concerning the fact itself.
Thus once cannot, pace Descartes, infer from the fact that one is certain about the distinction between one’s mind and body, to the fact that the mind and the body are in fact/in reality distinct.
It is not possible for (triangle) T to exist without P (the square of the hypotenuse is equal the square of the two sides)
What we seem to conceive of x, we really conceive of x
Arnauld’s argument rests on the fact that possibility precedes conceivability.
Thus Arnauld seems to deny this, Cartesian, form of argument:
If one can conceive of x that it is F and of y that it is not F, then x y.
If one entertains an idea of x being F and an idea of y being F-less, then x y
But ideas must be ontologically transparent, i.e. there is no gap between the idea and the thing it is about (cf. Wittgenstein’s Tractatus picture theory, where we have a one-one correspondence between words and objects).
That is, they cannot derivate (by abstraction) from other more basic and primitive ideas.
Yet we can maintain that they are different: the mind is a thinking thing while the body is an extended thing. As such they are different substances in which different attributes inhere.
Thus even if it is not really/actually possible for the mind to exist without the body it is logically possible—there is a possible world in which the mind exists without the body. While the mind is essentially thinking, the body is not. They are thus numerically distinct.
The exercise involved in thinking about one’s own mind is radically different from the exercise involved in thinking about an external object.
Two distinct objects/substances (e.g.: XYZ vs. H2O) may instantiate the same phenomenological properties. This is never the case when thinking about the mind.
I am not merely present in my body as a sailor is present in a ship, but that I am very closely joined and, as it were, intermingled with it, so that I and the body form a unit. If this were not so, I, who am nothing but a thinking thing, would not feel pain when the body was hurt, but would perceive the damage purely by the intellect, just as a sailor perceives by sight if anything in the ship is broken. … These sensations of hunger, thirst, pain and so on are nothing but confused modes of thinking which arise from the union and, as it were, intermingling of the mind with the body. (Sixth Meditation; CSM II: 56)
Descartes seems to give contrasting (contradictory?) answers.
On the one side, he said the soul resides in the brain (the pineal gland) and on the other side he said that it is coextensive with the body.
My next observation is that the mind is not immediately affected by all parts of the body, but only by the brain, or perhaps just by one small part of the brain, namely the part which is said to contain the ‘common’ sense. (Sixth Meditation; CSM II: 59)
[C]lothing, regarded in itself, is a substance, even though when referred to the man who wears it, it is a quality. Or again, the mind, even though it is in fact a substance, can nonetheless be said to be a quality of the body to which it is joined. … This is exactly the way in which I now understand the mind to be coextensive with the body—the whole mind in the whole body and the whole mind in any of its parts. (Sixth Set of Replies; CSM II: 297-9)
Descartes is aware of this problem.
Even though the mind is united with the whole body, it does not follow that it is extended throughout the body, since it is not in its nature to be extended, but only to think. (Fifth Set of Replies; CSM II: 266)
But in order to understand all these things more perfectly, we need to recognize that the soul is really joined to the whole body, and that we cannot properly say that it exists in any one part of the body to the exclusion of the others. For the body is a unity which is in a sense indivisible because of the arrangement of its organs, these things being so related to one another that the removal of any one of them renders the whole body defective. And the soul is of such a nature that it has no relation to extension, or to the dimensions or other properties of the matter of which the body is composed: it is related solely to the whole assemblage of the body organs. This is obvious from our inability to conceive of half or a third of a soul, or of the extension which a soul occupies. Nor does the soul become any smaller if we cut off some parts of the body, but it becomes completely separate from the body when we break up the assemblage of the body’s organs.
We need to recognize also that although the soul is joined to the whole body, nevertheless there is a certain part of the body where it exercises its functions more particularly than in all the others. It is commonly held that this part is the brain … because the sense organs are related to it ... the innermost part of the brain, which is a certain very small gland situated in the middle of the brain’s substance and suspended above the passage through which the spirits in the brain’s anterior cavities communicate with those in its posterior cavities. (The Passion of the Soul; CSM I: 339-40)
Existence thorough time: our body keep changing, yet it is the same as the one we got in our infancy.
That remains the same, though, are not the qualitative properties but its numerical identity. The latter is granted by the soul. The numerical identity of one’s body rests on the identity of one’s mind.
I consider what exactly is the body of a man, and I find that this word “body” is very ambiguous. When we speak of a body in general, we mean a determinate part of matter, a part of the quantity of which the universe is composed. In this sense, if the smallest amount of that quantity were removed, we would judge without more ado that the body was smaller and no longer complete; and if any particle of the matter were changed, we would at once think that the body was no longer quite the same, no longer numerically the same.(Letter to Mesland 9 Feb. 1645; CSMK III: 242-3)
[[B]y a body I understand whatever has a determinate shape and a definable location and can occupy a space in such a way as to exclude any other body; it can be perceived by touch, sight, hearing, taste or smell, and can move in various ways, not by itself but by whatever else comes into contact with it. For, according to my judgement, the power of self-movement, like the power of sensation of thought, was quite foreign to the nature of a body. (Second Meditation CSM II: 17)
It is wrong to consider the working of the brain and mind as separate from the working of the body.
The mind is part and parcel of the body.
E.g.: background feelings, i.e. the underlying awareness of the state that your body is in.
These signals provide a continuous update on the changes that our body state undergoes.
These background feelings provide our sense of ‘self’.
Hence, we wouldn’t be the same person if our brain were transplanted in another person.
For the body would provide different information.
New born babies tend to show only primary emotions (e.g. fear) which are innate and pre-organized.
As we grow we develop and make more use of secondary emotions which are primary emotions tempered by experience.
Emotions become associated with particular experiences. Thus their link with learning.
Are neurotransmitters produced in the brain.
They are also active in the human immune system and endocrine system.
Hence, they participate in the constant relationship between the brain and the body.