Professor Shelly Kagan gives a 48 minute lecture on the arguments both in favor of and against a non-physical soul. I will provide some additional information that was left out of the three points Kagan makes in his lecture.
Professor Kagan discusses in detail the argument of free will as proof for the existence of an immaterial soul. The argument consists of three premises: 1) We have free will. 2) Nothing subject to determinism has free will. 3) All purely physical systems are subject to determinism. The conclusion drawn from this is that humans are not a purely physical system; but Professor Kagan explains why this argument is not truly compelling. In addition, near-death experiences and the Cartesian argument are discussed at length.
00:00 – Chapter 1. The Dualist’s Stance on Free Will and the Soul’s Existence
04:57 – Chapter 2. Determinism and Free Will Cannot Coexist — Inspecting Incompatibility
15:22 – Chapter 3. Positing the Soul’s Existence for Near-Death Experiences
28:14 – Chapter 4. Does a Physical Understanding of Supernatural Phenomena Exist?
36:33 – Chapter 5. Introduction to Descartes’s Cartesian Argument: The Mind and the Body Are Not the Same
45:34 – Chapter 6. Conclusion
Complete course materials are available at the Open Yale Courses website:http://open.yale.edu/courses
This course was recorded in Spring 2007.
So let’s break down the three points Kagan mentions.
1) We have free will.
I’m not going to get into this one too deeply because if we don’t have free will, then everything we do is entirely pointless and there is no meaning to life at all. It seems completely self-evident to me that my interactions with this world are the result of free will on my part. I can say something and people can react to it. If no one had free will, the odds of random chemical interactions in my brain coinciding with the random chemical interactions of another person’s brain to produce the effect of having a conversation that neither of us has any control over seem to ridiculous to even consider. There is no way to explain interactions of multiple minds if both minds are the result of purely physical deterministic processes.
To his credit, at least Kagan concedes the existence of free will.
2) Nothing subject to determinism has free will.
In addressing this point, Kagan simply argues that determinism and free will ARE compatible. At time 14:00 he states that he will not present any evidence to say how this could be possible, but simply says the students should take it on faith that this is the case.
Color me unconvinced. Clearly this line of logic is absurd.
If all processes, including quantum processes, were completely deterministic, like billiard balls interacting with each other, then it should be clear that there can be no free will within such a system. It doesn’t take a rocket scientist to see the problems with Kagan’s line of reasoning here.
If Kagan’s line of reasoning were correct, then it should be theoretically possible to program a computer to become a conscious entity with free will using our existing technology. “Quantum” computers should not be necessary to produce this effect since, as Kagan argues, determinism is compatible with free will. Since existing computers are deterministic machines that can perform any kind of logical processing that their programmers desire them to accomplish, there is nothing theoretically standing in the way of building a conscious computer. By believing in compatibilism, Kagan believes that if a complex enough program were to be created, computers could suddenly become conscious entities that have free will.
I’ll leave you the reader to judge the merit of such an argument.
3) All purely physical systems are subject to determinism.
Kagan argues against this by invoking the magic of quantum physics. Without giving any details, he argues that because quantum physics is “the best” explanation of physical processes that we have today, and because quantum physics is a probabilistic theory, there is no reason to conclude that purely physical processes could not explain both free will and the mind.
I want to point out that by invoking quantum mechanics as an explanation for free will, Kagan is writing off any kind of macro process as being the cause of free will. Quantum physics is probabilistic only at the quantum level. You’ll never hear a scientist invoking probabilistic theory to explain the interaction of a nail and a hammer. All macro processes are deterministic in nature.
What Kagan never mentions in his lecture is, how does one go from a collection of inanimate quantum particles to conscious phenomenological experience? It is at this point that the EMERGENCE problem rears its ugly head. Kagan never once mentions the emergence problem in his lecture, yet the emergence problem is the most powerful evidence against a purely physical mind that exists. Obviously I am unsurprised to see that he never mentions it.
What Kagan is essentially arguing here is that if I arrange enough atoms in the right way, suddenly that blob of atoms will become a conscious entity that can “experience” the physical universe and engage in acts of free will.
This is like saying that if you arrange a block of iron atoms in the right way, suddenly you’ll get a block of gold. We know this to be absurd because in order to get a block of gold, one must fundamentally start out with GOLD ATOMS. No matter how many iron atoms you have, and no matter how you arrange those atoms, you will never get anything other than a block of iron from any given arrangement of those atoms.
From this, we can say that strong emergence is philosophically impossible. It can’t happen. You can’t take a collection of chickens and arrange them in such a way as to create a duck. The physical properties of the universe make it clear to us that any properties of a system must already be inherent in the components that make up that system.
So that leaves us with weak emergence. Weak emergence is pretty simple and I feel it pretty accurately describes our present universe. An example of weak emergence would be, if you start out will a blob of iron atoms, anything you create with that blob will have the properties of iron. This is pretty common sense stuff. If you want to add additional properties to the system, then you must do so by adding components that already have the properties you are wishing to add. If I want to make a gold and silver ring, then I must use gold and silver atoms in the creation of the ring. The properties of the ring directly reflect the properties of the components that were used to create it.
Weak emergence obviously leaves us with a problem. If consciousness, free will and “experience” are the result of weak emergence, then by definition atoms MUST be conscious! Does anyone honestly think that atoms are conscious? Is there any proof that atoms have components of consciousness within them? Of course not.
Since we know atoms are not conscious entities, and since we know strong emergence is philosophically impossible, both weak and strong emergence fail as explanations for consciousness, which also means that quantum mechanics fails as an explanation for consciousness.