B. Substance Dualism: Mind and body are distinct substances; they are radically different types of stuff. Mind is unextended and body is extended. This is Descartes's view.

C. Dual aspect theory: Mental properties cannot be reduced to physical properties but they are both just two different ways of looking at the same thing. This is Nagel's view.

	Descartes	Nagel, Aristotle	Science
Mind- Body Problem	Substance Dualism	Dual Aspect Theory	Materialism
Separate Substances w/ no interaction?	yes	no	no
Mind reducible to matter? No irreducible mental content?	no	no	yes
View of Self	Transcendent Agent	Emergent	Empiricist
Personal Identity	Soul	Memories, Personality	None (Body, Brain)
Immortality	yes	?	no
Free Will	yes	?	no

Hume's argument for this view:

When I examine the contents of my mind, I find only particular

sensations and perceptions.

I can find no sensation of my self.

-----------------------------

There is no substantial self, but only the various sensations and impressions that I perceive.

Since there is no self, agency or free will is impossible on this view. This view would be called Determinism.

B. The Transcendent Agent (homunculus): On this view the self is a non-natural (transcendent) entity, such as a soul, that stands behind all of our various perceptions or components.

On this view (agent causation), free will consists in having our actions caused by the self, which is free from natural causation. This view would be called Indeterminism. An argument for this view is that we all believe in free will and that only this view will make free will possible. The argument from responsibility (below) stresses our belief in moral responisibility as evidence for our belief in free will. One could equally well argue that denying free will lead to fatalism (the view that, since everything we do is determined, there is no point to attempting anything or taking any of our actions seriously). Therefore since none of us are fatalists, we must all believe in free will and in the existence of a transcendent soul.

If we have no self, we have no free will and cannot be held responsible for our actions.

But we all believe that we can be held responsible for our actions.

-----------------------------

Problem: If the soul does exist, how does it affect our thoughts and our bodies if it is immaterial? It is too disconnected from us to be the source of our personal identity. Once one subtracts all of the physically determined parts of your identity (your gender, your experiences, your habits, your genetic dispostions), there is nothing left to call the soul. This problem is highlighted by the following argument, which suggests that such a soul would be so irrelevant to our identity that we wouldn't even know if we had a new one.

Heart Full of Souls argument: (HFSA) (following Perry and Richard)

1. The soul is imperceptible.

2. Therefore, I have no way of knowing that I don't get a new soul every two minutes with all the same memories, etc., that I had before.

3. If the Soul is the source of my identity, then I have no way of knowing that I'm the same person I was two minutes ago.

4. I do know I'm the same person I was two minutes ago.

--------------------------------

The Soul can't be the source of my personal identity.

C. The emergent self: On this view there is no substantial self apart from or behind our various components. The self is the organized unity of these components. It emerges from the way the components work together as a unified whole. The self is more that just the sum of its parts on this view.

Free will consists of an agents actions being caused by the agent as a unified whole rather than by any one component of itself or by external forces. Thus even though the agent is determined by natural laws, it is free if it is determined by the laws governing itself as a whole rather than those governing it some of its parts or by outside forces. Views like this are often called Soft Determinism or Compatibilism, because they claim that having free will is compatible with the parts of an organism being physically determined.

This view often sees the self as analogous to the software of a computer, while the body is the hardware. Just as software can be transferred from one hardware or computer to another, this view would hold that the set of dispositions that make our personality and self might be transferrable from one substrate to another and, thus, make a type of immortality possible.

View	Considerations For	Considerations Against
Substance Dualism	1. Argument from Knowledge. 2. Argument from Extension 3. Makes Free will and Immortality easy to explain	1. Can't explain interaction of mind and body. 2. Uniform Correlation of mental events and physical events. 3. No violations of the laws of conservation of mass and energy. 4. Heart Full of Souls Argument.
Dual Aspect	1. Mind and Body Interact 2. Uniform Correlation of mental events and physical events. 3. No violations of the laws of conservation of mass and energy. 4. Nagel's Bat argument. 5. Jackson's Mary the Neurosurgeon argument 6. Ryle's College Analogy.	1. Argument from Knowledge. 2. Argument from Extension 3. Makes Free will and Immortality hard to explain 4. Only objectively verifiable events can be called real. (Pink Elephant argument)
Materialism	1. Mind and Body Interact 2. Uniform Correlation of mental events and physical events. 3. No violations of the laws of conservation of mass and energy. 4. Only objectively verifiable events can be called real. (Pink Elephant argument)	1. Argument from Knowledge. 2. Argument from Extension 3. Makes Free will and Immortality impossible to explain. (Argument from Responsibility) 4. Nagel's Bat argument. 5. Jackson's Mary the Neurosurgeon argument

© 2006 David Banach 

This work is licensed under a Creative Commons License.