What is it to Have a Mind?. What is it to Have a Mind?. Two Central Questions: What are minds? How do minds relate to/interact with bodies?. What is it to Have a Mind?. Recall our list of mental states: Thoughts Beliefs Desires Current experiences and sensations Emotions.
Two Central Questions:
Recall our list of mental states:
A mind is something that can be in such states as these.
But what is a mind and how does it relate to physical things like our bodies?
It is common to think that we are not just physical things, but that we have a non-physical nature.
Substance Dualism: There are substances of two fundamentally and irreducibly distinct kinds in the word: mental stuff, and material stuff.
According to substance dualism minds are immaterial things that are not made up of physical matter.
This lines up closely with the idea of that we have a soul or a spirit.
It is probably true that the vast majority of people are substance dualists:
In order to make sense of Descartes’ arguments it is useful to have the following principle:
Leibniz’s Law: If A and B are numerically identical then A and B share all of the same properties.
Qualitative Identity: A and B are qualitatively identical if and only if A and B have all the same properties.
Numerical Identity: A and B are numerically identical if and only if they are one and the same thing.
So Leibniz’s law says that if A and B are numerically identical then they must also be qualitatively identical.
(Not the reverse)
In other words, if A and B have different properties then they cannot be the same thing.
An example of how you might use the principle:
Argument from Doubt
I can doubt the existence of my brain and body.
This premise is supported by thinking about the evil demon scenario.
In such a case I don’t have a body or brain, so I can consistently doubt that I have a body or brain.
I cannot doubt the existence of my mind.
This follows from Descartes’ cogito. I cannot consistently doubt that I have a mind, because doubting is a mental state!
Therefore, my mind is not the same thing as my brain or body.
Follows from the premises by Leibniz’s law.
My body has a property that my mind lacks (being able to be doubted by me to exist) so they can’t be the same thing!
If this argument works, then it establishes that substance dualism is true:
There is problem with how Leibniz’s Law is applied in the argument from doubt.
Consider the following argument:
What if Manti Te’o reasoned as follows:
What is going wrong?
You can’t use what we believe, doubt, or can doubt about things in order to prove that they are not identical using Leibniz’s Law.
So we need an argument that does not make use of Leibniz’s law in this fallacious manner.
Fortunately Descartes gives us one!
“First, I know that everything which I can clearly and distinctly understand is capable of being created by God so as to correspond exactly with my understanding of it. Hence, the fact that I can clearly and distinctly understand one thing apart from another is enough to make me certain that the two things are distinct, since they are capable of being separated, at least by God……On the one hand I have a clear and distinct idea of myself, in so far as I am simply a thinking, non-extended thing; and on the other hand I have a distinct idea of body, in so far as this is simply an extended, non-thinking thing. And accordingly, it is certain that I am really distinct from my body, and can exist without it.” (Sixth Meditation)
The Conceivability Argument
The entire force of the argument depends on premise 1: the claim that conceivability entails possibility.
Despite the claim’s intuitive force, most philosophers think that it is false.
That is, it is possible for someone to conceive of something, without that thing being possible.
Steve knows about right triangles, but does not know the Pythagorean theorem (a2+b2=c2)
Suppose we ask him if it is possible to build a room in the shape of a right triangle with the following dimensions: 4x7x10.
He may very well say yes!
Furthermore, he may try to imagine the room, plan where he would put furniture in it, etc.
But such a room is impossible!
Hence, the fact that Steve can conceive of such a room does not entail that the room is possible.
Suppose I have amnesia and don’t remember my name.
I hear about this terrible instructor: Tim Butzer.
I imagine a world in which Tim Butzer is dead and I am attending a party to celebrate his timely demise.
But since I am Tim Butzer, it is impossible for Tim Butzer to be dead, and for me to be attending a party!
Hence, conceivability does not entail possibility.
Hesperus is the first visible star in the evening and Phosphorus is the last visible star in the morning.
Someone could imagine a case in which Hesperus is in the sky while Phosphorus is not.
Indeed they may think this happens every evening!
But Hesperus and Phosphorous are actually both Venus!
So every time Hesperus is in the sky Phosphorous is too (they are the same thing).
All three cases share a common feature: the subject in each is ignorant of some key facts about the case.
But it seems as if Descartes (or we) could be in precisely the same situation with regards to the relationship between minds and bodies.
Since conceivability does not entail possibility Descartes’ argument is not sound.
Therefore, we have no good argument for substance dualism.
All we have done is show that some arguments for dualism are not sound.
Next time we will look at arguments which attempt to show that dualism is false.
Papers Due on Thursday
According to the dualist:
But what does it mean for something to be immaterial?
Material things have certain kinds of properties:
Immaterial Object: Lacks spatial location, extension, solidity, motion, mass, or any physical properties
Dualists claim that minds are things of this kind.
But minds interact with physical things.
Interactionism: Minds interact causally with physical things.
Interactionism is an enormously plausible thesis.
It seems to be one of the most basic and obvious facts about minds that they are able to interact with bodies.
The main problem for dualism is that it seems to be inconsistent with interactionism.
According to every systematic theory of physics since Newton, every physical event in the universe has a physical cause.
This is in tension with the dualist’s claims that some physical events have mental causes.
Say that I raise my hand.
According to our best physics, there is a physical cause sufficient to produce this action.
According to the dualist there is also a mental cause for this action.
What the dualist has to say to be consistent with our best science is that my raising of my arm was causally overdetermined.
Causal Overdetermination: An event A is causally overdetermined if it has multiple causes, each of which would have been sufficient on its own to cause A.
There are many events in the clip that would prevent O.J. from making the arrest:
So, O.J.’s failing to make the arrest was causally overdetermined.
Causal overdetermination is clearly possible and sometimes happens.
However, as the clip also illustrates, such cases tend to be a matter of total coincidence.
As a result, though such cases are certainly possible, it seems that they are coincidental and rare.
The dualist must say that every time any person moves her arm, there is both a physical cause and a mental cause.
But this amounts to saying that there are a stupidly high number of mere coincidences happening all the time.
This massive coincidence calls out for some sort of explanation on the part of the dualist.
If mind’s and bodies interact, what explains the massive causal overdeterminationthat results?
Princess Elizabeth of Bohemia presents an argument which seems to show that dualism simply cannot be consistent with interactionism.
Elizabeth argues that if the soul is immaterial, by definition it does not have the kinds of properties that would allow it to causally interact with physical bodies.
What this shows is that if dualism is true, minds cannot cause bodies to move even in principle because, being immaterial, they lack the right kinds of properties.
“I confess that it would be easier for me to concede matter and extension to the soul, than the capacity to move a body and to be moved, to an immaterial being.” (179)
Elizabeth argues in terms of the physics of her day.
Today physicists recognize lots of other physical properties that can be causally relevant (charge, spin, field-strength, etc.)
But this doesn’t solve the problem for the dualist.
If something is immaterial it lacks physical properties. Whatever properties physicists uncover, the dualist is committed to saying that minds lack any of them.
Descartes’ most infamous response located the soul’s causal powers on the body in the pineal gland.
“The part of the body in which the soul directly exercises its functions is not the heart at all, or the whole of the brain. It is rather 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 slightest movements on the part of this gland may alter very greatly the course of these spirits, and conversely any change, however slight, taking place in the course of the spirits may do much to change the movements of the gland.” (The Passions of the Soul)
The idea seems to be that since the gland is so small and so central in the brain, that any little movement could have big results.
But thinking in this way completely misses the point of Elizabeth’s objection:
What Elizabeth’s argument shows is that dualism is incompatible with interactionism.
Therefore, why shouldn’t the dualist simply deny that minds and bodies causally interact?
The problem for any view like this is to explain observed facts:
If my mind does not causally interact with my body, how are we to explain these very common observations?
Malebranche suggested that every time you want to make your body move, God takes it as an occasion to intervene and cause your body to move in the way intended.
This doctrine is called occasionalism.
According to occasionalism the laws of physics are violated every time I “move” my body.
Every time any person move’s their body is literally a miraculous event!
Leibniz suggested that the apparent interaction was due to a pre-established harmony:
Think of two clocks set to the same time. They don’t causally interact, but they can be such that they always agree on the time.
Leibniz’ idea is that the relationship between the mental and physical is a lot like that.
Both Malebranche’s view and Leibniz’ seem to be theoretic acts of desperation.
Since dualism is inconsistent with this kind of interaction, it must be rejected.
Let’s adopt Elizabeth’s suggestion and consider the possibility that the mind is a material thing of some kind.