Rene Descartes
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Rene Descartes
Gilbert Ryle
William Lycan
John Searle
Group Project #2

BIOGRAPHY: French philosopher, mathematician, and scientist. His philosophy is called Cartesianism (from Cartesius, the Latin form of his name). Born in La Haye, France, and trained at the Jesuit College at La Flèche, Descartes remained a Catholic throughout his life, but soon became dissatisfied with scholasticism. While serving in the Bavarian army in 1619, he conceived it to be his task to refound human knowledge on a basis secure from skepticism. He expounded the major features of his project in his most famous work, the Meditationes de primaphilosophia (1641, Meditations of First Philosophy). He began his enquiry by claiming that one can doubt all one's sense experiences, even the deliverances of reason, but that one cannot doubt one's own existence as a thinking being: cogito, ergo sum ("I think, therefore I am"). From this basis he argued that God must exist and cannot be a deceiver; therefore, his beliefs based on ordinary sense experience are correct. He also argued that mind and body are distinct substances, believing that this dualism made possible human freedom and immortality. His Discours de la méthode pour bien conduire sa raison, et chercher la vérité dans les sciences (1637 Discouse on the Method for Rightly Conducting One's Reason and Searching for Truth in the Sciences) contained appendices in which he virtually founded co-ordinate or analytic geometry, and made major contributions to optics. In 1649 he moved to Stockholm to teach Queen Christina of Sweden.

Perhaps the most popular view about the relationship between mind and body is DUALISM -- the belief that mind and body are two separate entities, and that the mind is essentially non-physical (and hence is beyond the reach of the physical sciences). Descartes is most associated (in modern times) with this view. Dualism comes in a variety of forms, which are distinguished by how they describe the relationship between the mind and body. Here are but some of the possibilities:

INTERACTIONISM: An interactionist believes just what the name implies -- that mind and body interact. Mental activities (believing, desiring, intending, hoping, etc.) can therefore cause changes in the body (i.e. my belief that I am in danger can cause me to sweat profusely, to run away from the perceived cause of that danger, etc.), and physical changes can likewise cause mental events to occur (stubbing my toe causes pain,etc.) The challenge for this view is to explain how a non-physical thing (the mind) can bring about a change in a physical thing (the body), and vice versa.

EPIPHENOMENALISM: Here mind and body are separate, but the mind is created or caused by the brain. ("Epi-" is a prefix from the Greek that means "above" -- hence to characterize mental activity as epiphenomena is to claim that such activity is above or outside of physical phenomena.) This is an odd sounding view, but it has two appealing traits -- first, it allows us to hold onto our belief that we have mental states which are more than simply physical properties of the brain; and second, it seems less "spooky" than interactionism because it makes the physical (the brain) the cause of the mental (as opposed to being a wholly separate entity). There are two types of epiphenomenalists -- those who are interactionists (who believe that mental properties, though caused by the brain, can affect the brain, and vice versa), and those who are not (who claim that the brain can affect the mind, but the mind cannot affect the brain). The problem for the interactionist epiphenomenalist is the same as for the plain-old interactionist -- explaining how mind and brain interact. The non-interaction version of epiphenomalism inherits this problem as well, and a different one. It seems clear that our mental life does bring about physical changes (as our earlier example of perceived danger suggests). The non-interaction epiphenomenalist denies this...and that's a problem.

PARALLELISM: The difficulties of explaining the interaction between mental and physical led some to posit parallelism, the view that mind and body do not interact at all, but simply run in parallel. Imagine two clocks side by side, each displaying the exact same time. Though in perfect synchronicity, neither affects the other. Thanks to God, our mental life and physical life mirror one another perfectly, but only because they were designed this way, and not because they interact. Hence on this view, when I stub my toe, I get the mental sensation of pain NOT because the physical act of stubbing my toe CAUSED the pain, but because my mental life was designed to have an experience of pain at that very moment. All works in pre-established harmony. The advantage of this view is that it allows one to hold onto the notion that mind and body are different, without needing to explain how they interact. The challenge for this view is that it requires not only a belief in God, but a belief in predestination (that one's mental and physical life are already fully determined) which raises other problems with the notion of freedom of the will, etc.

Descartes offers 2 arguments that the mind and body are separate. PRINT OUT THIS PAGE AND BRING IT TO CLASS. I will expect you (1) to explain arguments (A) and (B), (2) to suggest possible criticisms for these arguments, and finally, to come with a WRITTEN response to part (C).

(A) The argument from divisibility (first paragraph, p. 77)

1. My body is divisible into parts.

2. My mind is not divisible into parts.

3. (IMPLIED PREMISE: Two objects (A and B) are identical only if the properties of A are properties of B.


4. Therefore, my mind and body are not identical.


(B) Animal and human nature (first full paragraph, p. 79)

1. Animals (especially higher mammals) possess almost all the same organs and physical structure that humans do.

2. Animals cannot think; humans can.


3. Therefore, humans must possess some faculty animals do not possess.

4. But given (1), that faculty cannot be physical (or based in physiology).


5. Therefore, humans possess a non-physical mind.


(C). Explain the two tests (p. 190) which Descartes believes we can use to distinguish real persons from machines (or automatons) that only resemble persons.