# Descartes and Dualism

## January 22nd, 2020

- "Sometimes I forget how dense Descartes is; the work is short, but it has many small, intricate arguments"
- Anyway, on today's agenda is:
    - Homework for Monday/Wednesday
    - Go over homework for today
    - Review Meditations 3-5
    - Meditation 6 (existence of the external world, nature of material world, substance dualism)
- "Next week, we'll also read some correspondence Descartes had with Princes Elisabeth of Bohemia, and since it's the 17th century they're *super* polite to one another"
- Your 1st homework assignment is due SUNDAY NIGHT, so be aware
    - "I'm basically grading these on a 1 to 5 scale, and not super-harshly"
    - These homeworks are supposed to be short, 1-2 paragraph responses; I'm expecting 250 words (or at MOST 500), but they should still contain well-thought arguments
    - As always, be respectful; you're not impressing anyone by dunking on people on a course website
--------------------------------------------------------------------------------

- Okay, let's look at the wax premise on your handouts
    - By "perceiving through the mind alone," Descartes means he understands what the wax is through his mind
    - By "imagination," he means calling to mind a picture/representation of something
    - "Descartes is trying to get us to see science as built on rationality, and NOT on human perception, by turning our gaze inwards"

- Last time, I tried to explain what Descartes means by "clear and distinct;" ideas; I think I can do better, so let me go over that again
    - Essentially, these are ideas that we cannot doubt that deal with the essential nature of things, and are "innate" in some sense
        - Descartes spent much of Meditation 3 grounding the truth of these in God
        - "Descartes *is* being sincere in arguing for God here, but he's also really interested in trying to appeal to the church to support his rational and scientific investigations"
    - If God isn't a deceiver, though, why isn't Descartes right all the time? In Meditation 4, he says it's basically because his will to know is greater than his actual knowledge, and so he sometimes makes rash errors by going beyond the evidence his senses give him
    - In Meditation 5, he introduces yet another argument for God
        - We'll unfortunately skip this one for time's sake, but note that by "God" Descartes has a VERY particular notion of an infinitely real, infinitely good being ("good" not just in a moral sense, but in the sense of not lacking anything)

- Okay, let's look at Meditation 6, where Descartes tries to tie everything together
    - Descartes is now trying to show the material world really DOES exist!
    - Next, he tries to reason about what essential properties this world must have
    - Finally, he argues for a classic position known as "substance dualism"

- On pg. 64, Descartes claims everything he's "taught by nature" has some truth, for instance, if he's next to a fire and feels the warmth, he has an impulse to believe that fire has *something* to do with the warmth
    - Essentially, if he can't prove something is false, and we have a great inclination to believe it to be true, we can trust our senses, since God isn't a deceiver and he made these senses
    - Of course, there's a bunch of questions here: what does Descartes mean by a "perfect" being? He is NOT talking about morality, but about completeness (although people have quibbled over how well he's proved honesty is a piece of this)

- So, what's the material world?
    - Descartes is NOT saying his senses are always right, but he is saying that we're perceiving things that are actually there - and in particular, he says we can understand them through math!
        - Whaaaa? Well, Descartes thinks of the world as matter on a 3D Cartesian plane, and that it can be understood mathematically and rationally investigated
        - "Why can he trust this? Well, an awful lot is riding on the idea that God isn't a deceiver!"
    - As a side note:
        - "By the light of nature" essentially means clear and distinct ideas Descartes has, while "taught by nature" mean things his senses give him an inclination to believe

- Okay, let's talk about substance dualism *really* quickly
    - Descartes concluded in Meditation 2 that he at *least* knows he exists as a mind, but he can't prove that for the material world in the same way
    - Because of that, Descartes thinks the world has 2 substances: thinking things, and matter, each of which can take on different "modes"/forms
        - So, Descartes would say we're distinct from material stuff, and "we" are really made up of thinking stuff
        - He offers 2 arguments for this: 1 easier, and 1 more complicated
            - The easier one is his "indivisibility argument," which says that since there is no clear way of dividing the mind into parts as you can all physical matter, they must be essentially different!

- Alright, over the weekend more about this substance dualism, that the mind is different in *kind* from matter. Enjoy!