The philosophy of mind is one of my strongest research interests. Of all the subjects that I’ve encountered in my years as a student, not a single one has proven itself to be as fascinating and endlessly entertaining (not to mention incredibly difficult) as this one. As such, I’d like to share with you some of the basics of the field. I’d like to discuss the major issue that leads to pretty much every other issue about the mind, and then briefly describe some of the various positions that have been put forward as answers to the major problem in the philosophy of mind.
Philosophy of mind starts when we ask ourselves: “What is the mind? What is the brain? How are the two related?” At least one of these questions seem easy enough to answer. We know where the brain is so we can just point to it, and there we have it, question answered. But it really isn’t that simple. Sure, we know where the brain is, and we know it does some things up there in our skull, but what about the mind? Is the brain causing the mind? Is it simply identical with the mind? Where the hell is that mind, anyway? I see evidence of my mind everywhere, but where the hell is my damn mind?!
We’ve all heard the old phrase “I lost my mind.” But did we ever have it? I can’t find it. I search and search for it, but there is no mind to be found. The only way I know that I have a mind is because I am searching, and I realize that I am searching, and I realize that this realization itself confirms that I have a mind. And this is exactly how René Descartes arrived at his famous cogito ergo sum (I think, therefore I exist). Through the act of thinking itself, one has sufficiently proven to oneself that one is a thinking thing. And what else could a thinking thing be, but a mind? Descartes used this existence proof to anchor his entire philosophical system, proceeding in a stepwise manner to every conclusion thereafter.
Through a methodical process of skeptical doubt of everything that can possibly be doubted, Descartes reasoned that the mind must not be a part of the body itself. We can never be sure that we’re in this body that we see. My hands, typing on this keyboard, may not be real. We could be living our lives in a virtual matrix, like the one from the popular science fiction film. So we cannot be sure of our bodies. But our minds…. of course we are certain about our minds! We couldn’t be in the matrix without a mind to perceive it. If there were no mind, there would be no “I” to speak of.
So now we can address the formal category of Descartes’ philosophy of mind: Dualism. Dualism is probably the longest-living view of the mind in existence, as it can be traced back far beyond Descartes’ time. Dualism holds that the mind is (or resides in) a separate substance from the substance of physical matter. There aren’t any good explanations (to my knowledge) out there of exactly what this mind-substance is, other than the fact that it is non-physical. So Dualism is the thesis that there are two “realms,” one non-physical (where our minds, souls, and presumably also God and all other ethereal beings that have been dreamt up over time reside), and one physical (where everything that we come into contact with on a daily basis resides).
The most common form of dualism is like Descartes’ version. It is called ‘Interactionist Dualism,’ meaning that the non-physical mind can interact with the physical world and have physical effects (e.g., you mentally desire some bacon, so you physically get up and make some bacon), and in turn the physical world can have mental effects (e.g., you have eaten so much bacon that you are now full and desire a nap). I keep these examples limited to desires alone, since it is unclear whether or not sensory perception is considered by most Dualists to be non-physical in nature. Things like desires and beliefs, however, are most universally considered to be purely mental, and hence non-physical, constructs.
The problem with Interactionist Dualism, as you may have already realized, is that it is entirely unclear how things that are non-physical could possibly have physical effects. We can understand physical causation because we see it in action every day. When one billiard ball smacks into another, they tend to roll off in different directions. There is a clear transfer of energy and motion in physical causation. What happens when two minds smack together? Does this question even make any sense? Indeed, it seems that it would take quite an imagination to conjure up a set of rules for non-physical causation, whether we are discussing the interaction of two non-physical things or one physical thing with a non-physical thing.
A highly influential modern philosopher by the name of Gottfried Wilhelm von Leibniz tried to dodge this problem of interaction with his view called Parallelism. Leibniz called upon God to settle this problem. God set up a “pre-established harmony” so that the physical world and the mental world would appear to completely coincide with each other. While physical things can only interact with each other and non-physical things can only interact with each other, to anyone that is not God (or apparently Leibniz), it appears as though our non-physical mental states are causing effects in the physical world directly. But this is just an illusion, set up by God. A similar view is one called Occasionalism, which holds that God, and only God, is the direct cause of all events. So there is no need to worry about the apparent interaction problem, since nothing interacts except with God. Nicolas Malebranche is a well-known proponent of this view.
A more modern approach to the mind-body problem is one called Property Dualism. Unlike Substance Dualism, which posits two fundamental substances, Property Dualism holds that there is only one substance, physical matter, but this homogenous matter can have two kinds of properties: mental and physical. So our beliefs and desires and the rest of our mental states that are held to be of a non-physical substance by Substance Dualists are actually just non-physical mental properties that reside in physical matter. If you’re confused by this, don’t worry. It is a very strange view to grasp at first. But the basic idea is that mental properties are somehow “over and above” physical substance. On most accounts, it is held that the brain is the physical substance in which all of our mental properties reside. So the brain somehow “produces” mental properties that are not reducible to a set of physical facts. Now, as much as I would like to go a bit further into the different types of property dualism (supervenience, epiphenomenalism, etc.), I’m afraid that this territory is too murky for a novice like myself to be leading others into it. The notions of supervenience and epiphenomenalism are a bit unclear at best, and so I will conclude my discussion of Dualism here.
So during this post, we have familiarized ourselves with some common and notable forms of Dualism. I dedicated a lot of space to this view because it is so influential in the world at large, not just among philosophers. It is likely that most everyone is some kind of dualist. Given the heavy influence of religious traditions in our world, most people desire to hold on to the idea that there is some non-physical reality, and the confusing aspects of the mind find themselves quite at home in this realm. Indeed, for most people, leaving the mind in the non-physical world is a much better option than trying to figure out exactly how a world of only physical objects could give rise to anything like conscious experience and mentality. And it will be in my next post that I will attempt to shed light on some of the views and theories that try to explain how a materialist (and also at least one ontologically neutral) view of the mind can still plausibly account for the nature of our minds.