I. Luke and Darth
Let's say you don't know much about Star Wars, and for some reason you suspect that Luke and Darth Vader might be the same individual. One way you could solve this is by looking at the properties of each one.
- 5 feet 7 inches
- can breathe on his own
- blond hair
- nice skin
- 6 feet 6 inches
- requires a breathing apparatus
- pale, veiny skin
- If X = Y, then whatever is true of X must be true of Y and vice versa. If there are properties true of X but not true of Y, then we can conclude that X and Y are not the same individual. That in fact there are two individuals, not one.
So the same thing applies to mind and body, or rather mind and matter. Mind has several properties that are apparently not properties of matter, at least at first glance:
- Private to the individual who has it
- Thoughts are about things. Thoughts have meaning.
- Subjective experience. Red looks a certain way.
- Public. Anyone can observe matter.
- Meaningless. Unless we assign meaning to a certain parcel of matter (like an arrow, say), it has no meaning.
- No qualitative properties. The color red is a certain wavelength, but described in purely physical terms, it is devoid of the way red looks.
Dualism is the view that mind and matter are two separate fundamental entities. So would have a physical body, and then a non-physical mind sort-of "inhabiting" the body. This view is appealing to those with religious or other spiritual convictions, because it is more friendly to the idea of life after death. There is a serious flaw in it, however.
From modern empirical science, such as as the law of conservation of energy, we have good evidence that all physical effects have physical causes. Electrons and quarks are moved around by other physical particles or forces. In short, there is no evidence, and plenty of evidence against, the idea of telekinesis. So how can these apparently non-physical mental properties affect physical matter, such as when you raise your arm? There is no good model for this interaction, and plenty of evidence against it. Which is why we might want to look to alternatives...
One possibility is to eliminate the need for the mental to affect the physical. The matter of the brain causes the non-physical mental elements, but not vice versa. The mind is just a phenomena that arises from the brain as a sort of byproduct, but can have no effect on anything physical, much like steam coming from a locomotive arises from the action of the engine but plays no role itself in the forward motion of the train. This view, called epiphenomenalism, is less than ideal, however. My mind is grasping the idea of philosophy of mind and is causing my physical fingers to type this article. We obviously want to say that the mind can affect the physical body, and so we might instead want to leave epiphenomenalism behind and explore materialism, the view that mind is just matter. This would be the most parsimonious theory, if possible.
There are three main ways of explaining mind in terms of matter. Consider as an analogy the example of a bronze statue. You could describe it in several different ways:
- The statue consists of a hunk of bronze, but is its own separate thing and is not just a hunk of bronze. The statue would not exist without the bronze but the statue has its own properties that are different than just the hunk of bronze.
- The statue really exists, but what it is is nothing more than a hunk of bronze. All talk of the statue can be reduced to talk of the hunk of bronze.
- There is no statue. There is just a hunk of bronze.
- The mind arises from matter, but is not reducible to it. It's its own thing. The problem here is that the physical events of the brain are enough to explain the movement of the body and other physical effects; there is no room or need for mental events, and so they become a dangler that doesn't actually cause anything, like epiphenomenalism above. This is, as shown above, less than ideal for an explanatory theory of mind.
- The mind is reducible to matter. There is a mind, but what it really is is nothing but physical events in the brain. This means that talk of the mind is fully replaceable by talk of physics. The problem here is that mental properties are just not the same as physical properties, as seen above. Privacy, qualia, and meaning are all properties that are simply not present in physics. Another problem with this view is that it may entail the elimination of the mind. If we say that there is a mind, but what it really is is just the physical brain, then we are really saying that there is no mind. There is just the physical brain. There is one thing. not two.
- And the final version of materialism is just to eliminate the mind. To recognize that the above mental properties can never be explained in terms of physics, and therefore to just eliminate them entirely from our worldview. The problem with this view is that science and reasoning in general depend on such mental concepts as meaning, and rational analysis requires the use of reasoning on the meaning of premises to a meaningful conclusion. So elimination of the mind might be self-defeating and completely destructive of the very things we think we know.
None of the theories offered here seem all that spectacular. Materialist reduction in science has proven to be a terrific success, but the human mind tends to still be resistant to easy explanation. Some think that this is because of in-principle problems with the materialistic worldview, and not just an explanatory gap. Others think that that the mind will eventually succumb to material reduction, but at this point the debate is still wide open.