The Mind vs The Brain
Jun 10, 2023
Consciousness is a topic of heavy contention in the philosophical world. The debate largely centers around the mind and the brain, and whether these two entities are synonymous. Are we simply the result of trillions of neurological connections, or is there something more metaphysical at play? There is little conclusive agreement in this discussion.
Cartesian Dualism, more commonly called Substance Dualism, is a philosophical position that asserts that the mental and physical states are distinct. This implies that the mind and the brain not only differ, but actually are separate entities entirely. This theory claims that mental states exist abstractly outside of the physical brain, and that these mental states interact with your physical mind and body. For example, substance dualism would describe consciousness as a mental state that has no physical embodiment, while a tangible action, like breathing, exists in the physical world. Another mental state may be homesickness, and the brain state is the physical configuration of the brain at that moment. In this way, Cartesian Dualism is also a causal theory, as it holds that mental states are what cause brain (and therefore physical) states. For example, the mind wills the body to walk forward or to type a test response through a causal connection between the mind and brain.
Herein lies a potential problem- the interaction between mental and physical substances may involve a causal impossibility. Immaterial, and therefore abstract objects are separated from physical reality in the sense that they are not limited to material laws in the way that our physical states are. The mind in Cartesian Dualism has no shape, size or matter, it is purely abstract like the concept of the number 1. Physical objects, such as our brain and body, interact causally only through physical interaction with other physical objects. It is therefore impossible for an abstract object to cause a physical state and there is no way to establish a physical connection. There is no mechanism by which to connect ontologically distinct realms of reality. A mental state inducing a physical state is akin to an imaginary tennis racket hitting a real tennis ball, or an imaginary truck transporting very real boxes. We know this interaction to be impossible, and there is no reason to suggest that our minds are exempt from this sort of physical impossibility.
The problem of interaction is further supported by what is known as the Causal Closure Principle. The principle is as follows: If a physical effect has a cause, then it has a sufficient physical cause. In effect, this principle supports the problem of interaction in two ways. First, the causal closure principle is based on the conservation of mass-energy (energy cannot be created or destroyed), and Substance Dualism implies that an abstract event with no physical mass-energy can cause/create a physical event. This is fundamentally against the laws of thermodynamics. It would be similar to me moving a bookshelf by only imagining the bookshelf moving. Input energy is needed for the bookshelf to physically move. Second, the Causal Closure principle recognizes that a chain of causal interactions has never required an immaterial cause for explanation. We can fundamentally explain any physical event with a determinist view of particles interacting with each other. No abstract objects have ever been needed for this explanation so it does not hold that mental states have any reason to exist abstractly. For example, I can fully explain why my knuckles hurt today in physical causality: I was mad (that is to say my brain state configuration and neurons interacted to give me the feeling of mad). Because I was mad I punched a tree, and because I punched a tree my knuckles now hurt. No mental causation is necessary to explain this causal chain.
The antithesis to Cartesian Dualism is the Identity Theory of the mind, which states that mental states and brain states are one in the same. The Identity Theory is based completely in physical terms. For example, my emotional state right now (sad and tired) is simply the combination of millions of neurons firing in a specific sequence. Additionally, if I see a shark, the fear I experience is not due to any abstract mental state, rather it can be fully explained in physical terms. This is a very logical and convincing theory, but it too is not without criticism.
The Conscious Experience Argument, which argues against the identity theory of the mind, has two major premises.
1. If mental states are identical to brain states, then it is possible to know everything about the mind by knowing everything about the brain.
The rationale of this premise is that if mental and brain states are one and the same, then we should be able to fully describe someone's mental state with enough physical empirical evidence. If two things are identical, knowing everything about one should tell you everything about the other. In fact, if two things are identical there is, for all practical purposes, only one thing. For example, say an orange represents a mental state. If I was to know the exact atomic configuration of every particle within the orange at a given time, I could essentially define the orange. This description is identical to the orange that was taken at face value. The same should be true with a mental state. If I was to know every detailed particle of the brain at a given point, its description should be identical to that of the mental state being experienced.
2. The second premise argues that it is not possible to know about the subjective conscious experience by knowing everything about the brain.
This premise essentially argues that subjective feelings are not purely a matter of physical state. For example, both you and I can look at a green shirt, however, while we have the same conscious experience, we feel certain things toward the shirt individually. The color green may mean something different to me than it does to you. This is called qualia, or a subjective mental state. Another good example of this is our memories. Two siblings remembering the same event have their own subjective feelings toward the memory. The way we visualize events in the past cannot be explained by our brain state at the time.
Additionally, each person's emotions may be entirely different. What I experience as pain could be what you experience as ecstasy. (or I suppose if you're a masochist these are one and the same). Regardless, we may both feel pain, however, our subjective experiences of this emotion is completely unique, we experience it individually.
The reason I like this debate so much is that it soon may be solved. Neuroscientists are confident that AI may soon be able to digitally visualize dreams in real time based on EEGs and relative levels of brain activity. Questions in philosophy are slowly chipped away as our understanding of the world becomes scientifically verified, and it may be that the mind vs the brain debate may be next on the philosophical chopping block.