Philosophy 1050: Introduction to Philosophy

1. Philosophy 1050: Introduction to Philosophy Week 11: Descartes and Dualism: The Mind/Body Problem

2. Descartes: Mind and Body • So far, Descartes has argued that he exists as a thinking thingdefined by its capability of thinking, perceiving, and imagining. • He has also argued that, since God exists and is not a deceiver, there is reason to believe that the external world exists and is (more or less) how we perceive it to be. • In the Sixth Meditation, he now will consider how his mind (or thinking substance) is connected to his body (or extended substance)

3. Descartes: Mind and Body • Descartes argues that there is a real distinction between the mind and the body: • “…Because on the one hand I have a clear and distinct idea of myself, insofar as I am merely a thinking thing and not an extended thing, and because on the other hand I have a distinct idea of a body, insofar as it is merely an extended thing and not a thinking thing, it is certain that I am really distinct from my body, and can exist without it.” (78).

4. Descartes: Mind and Body • Extension is the property of taking up space. If something has a size or a shape, it is “extended.” • According to Descartes, the body (like all bodies or objects) is extended but not thinking. The mind is thinking but not extended.

5. Descartes: Mind and Body • Descartes has two arguments for the real distinction between mind and body: • 1) The body can be separated from the mind, or the mind from the body. • 2) Mind is indivisible, whereas bodies are divisible: “For when I consider the mind, that is, myself insofar as I am only a thinking thing, I cannot distinguish any parts within me; rather I understand myself to be manifestly one complete thing…On the other hand, there is no corporeal or extended thing I can think of that I may not in my thought easily divide into parts.” (86)

6. Descartes and Dualism • According to Descartes, therefore, we are made up of two essentially different kinds of “stuff” or “substance.” Mind does not take up any space and has no physical existence. Matter does take up space and has a physical existence. We are made up of both, mind and body. • This view is sometimes called “dualism” or “Cartesian dualism.”

7. Descartes and Dualism • According to Dualism, what is responsible for thinking and consciousness is not the brain (which takes up space and is physical) but rather the mind, which is not physical. The (physical) brain is closely connected with the (nonphysical) mind, but they are still different things.

8. “My second observation is that my mind is not immediately affected by all the parts of the body, but only by the brain, or perhaps even by just the small part of the brain, namely, by that part where the “common” sense is said to reside.” (86)

9. Descartes and Dualism • According to Descartes, the eyes perceive objects and then focus the image on a central part of the brain. This part of the brain then “transmits” the information to the non-physical mind. The mind may then transmit back a signal telling the brain and body how to move or act.

10. Descartes and Dualism • Descartes thought this “transmission” of information from the physical brain to the non-physical mind and vice-versa worked through the pineal gland, a central part of our brains. • We now know that the pineal gland helps to regulate hormones in the brain as a whole.

11. Descartes vs. Modern Science: Dualism vs. Physicalism • Does Descartes’ story about the link between the physical and the non-physical make sense? • Does it involve a “miracle” that we can’t explain scientifically?

12. Descartes vs. Modern Science: Dualism vs. Physicalism • Modern science (biology and psychology) is based on the assumption that the physical brain, rather than a non-physical mind, is responsible for all thought, consciousness, and behavior.

13. Descartes vs. Modern Science: Dualism vs. Physicalism • Some philosophers have described the view of modern science as “physicalism.” According to physicalism, everything that exists and that we are made up of is ultimately physical or material. There is the physical body, and the brain, but there is no additional non-physical mind or soul.

14. Descartes vs. Modern Science: Dualism vs. Physicalism • If physicalism is true, then all our thought, consciousness, and behavior can be explained in terms of the brain and nervous system. All that we are is our bodies and our brains.

15. Descartes, Dualism and Modern Science: Summary • Having doubted and then proven the existence of the external world, Descartes argues that we are made up of two distinct substances: thinking substance or mind and extended substance or matter. • He believed that the mind influences the brain and body, and vice versa, but that only the non-physical mind can truly be conscious and thinking. • Modern science, by contrast, usually takes the physicalist view that all consciousness, thinking and behavior can be explained in terms of the physical body and brain, with no reference to a non-physical mind.