1. Descartes’ Interactionist Dualism

2. Overview Descartes’ general project Descartes’ general project Argument for dualism Argument for dualism Explanation of mind/body interaction Explanation of mind/body interaction

3. Descartes’ General Project To secure a firm, certain foundation for the sciences To secure a firm, certain foundation for the sciences To prove the existence and goodness of God To prove the existence and goodness of God To show how the soul could be immortal To show how the soul could be immortal

4. The Argument for Dualism I have a mind. I have a mind. My mind is not my body. My mind is not my body. I have a body. I have a body. Therefore, I have both a mind and a body, which are distinct from one another. Therefore, I have both a mind and a body, which are distinct from one another.

5. Argument for Having a Mind Descartes considers what it is possible for him to doubt, and concludes that it is impossible for him to doubt that he thinks. Descartes considers what it is possible for him to doubt, and concludes that it is impossible for him to doubt that he thinks. He cannot doubt that he thinks because, in doubting, he is thinking. It is not possible for him to think “I am thinking” without being right. He cannot doubt that he thinks because, in doubting, he is thinking. It is not possible for him to think “I am thinking” without being right. So, he concludes he is a “thinking thing,” i.e., a mind. So, he concludes he is a “thinking thing,” i.e., a mind.

6. Argument for the Existence of Bodies It seems to me that there are bodies, and that I have one. It seems to me that there are bodies, and that I have one. God is too good to allow me to be deceived about something so fundamental and important. God is too good to allow me to be deceived about something so fundamental and important. Therefore, there are bodies, and I have one. Therefore, there are bodies, and I have one.

7. The Mind is not the Body 1. If the essence of a kind of thing x is y, then there could be no x without y. (premise) 2. The essence of body is to occupy space. (premise) 3. For any kind of thing x, if I can imagine an x that lacks some property, God can make an x without that property. (premise) 4. I can imagine a mind that does not occupy space. (premise) 5. Therefore, God can make a mind that does not occupy space. (from 3, 4) 6. Therefore, the essence of mind is not to occupy space. (from 1, 5) 7. Therefore, the mind is not the body. (from 2, 6)

8. Interaction If the mind and body are distinct, we need an explanation of how mental and physical events can cause one another. If the mind and body are distinct, we need an explanation of how mental and physical events can cause one another. Descartes tells a story about the mind and the body “communicating” through the pineal gland. Descartes tells a story about the mind and the body “communicating” through the pineal gland. What problems with this story might there be? What problems with this story might there be?

9. Review Descartes wants to prove dualism because it allows for the immortality of the soul. Descartes wants to prove dualism because it allows for the immortality of the soul. The argument for dualism turns on a perceived difference in the essences of mind and body. The argument for dualism turns on a perceived difference in the essences of mind and body. Descartes probably does not solve the problem of interaction. Descartes probably does not solve the problem of interaction.