The Philosophy Cafe

The Philosophy Café at Harvard Book Store is a monthly gathering meant for the informal, relaxed, philosophical discussion of topics of mutual interest to participants. No particular expertise is required to participate, only a desire to explore philosophy and its real-world applications. More information can be found at www.philocafe.org.

The Philosophy Café is held on the third Wednesday of each month at 7:30 in the Used Book department on the lower level of Harvard Book Store.

This month:

Monism vs. Dualism, or Matter vs. Mind

Is the physical world all that really exists? The idea that the real is only one thing, or one kind of thing, is monism. The belief that this one real thing is the physical world, the things and forces that exist in space, is the most common form of monism—also known as materialism, or physicalism. A less prevalent form of monism says that the mental is all there is, but generally, today, the action is in the disagreement between physicalists, who say that only the physical is real, and those who say that the physical is real, but the mental is too.

What does it mean to say that there is another kind of thing than the physical—call it mind—that is just as real as matter? 

Mind is a more modern way of describing the non-physical. Once most people would have been more likely to call it the soul. There was the soul and the body. The soul was a thing, in a way similar to the body, except that it had no material substance and lived on without the body after death. This belief is not so prevalent among philosophical dualists today. Most would not say the mind is a thing in quite that way. But it might exist separately from the body—not in the old sense, but at least in the sense that if I write a book, for example, it would contain a piece of my mind which could exist after my death. But many people would find this “existence” metaphorical, compared to the old idea of the soul.

Monists say that what we call mind is only a name for certain patterns of matter and energy. The “mental” is an illusion, reducible to the physical. All we can objectively observe, they say, is the physical. We can’t discover any mental “substance” any more than we can discover ghosts. The mental is often called the ghost in the machine. How can you believe that this ghost is real, and what could that mean?

Some dualists say that mind is an essential capacity of people. We can see new situations, reason about them, and decide what to do next. This capacity for acting on the basis of reasons is also called free will. Monists, or many of them, would say that we don’t have free will, and that our reasons are epiphenomena, which can be caused by the movements of matter but which cannot cause matter to move. The idea, and the feeling, that mind moves matter is an illusion.

Dualists say that the illusion is that mind does not move matter. We examine the situation, decide what to do, and do it. We can’t explain people’s actions without talking about their reasons for doing what they do. Of course matter—the physical—influences mind. For example, we may talk more freely, and also become more muddled in our thinking, when we’re drunk. When we’re depressed we can take antidepressants. We can take drugs that help us concentrate better. But these are general effects. To influence specific beliefs and actions we need reasons, arguments, persuasion. To a monist—or most of them—all reasons are rationalizations. Their causal efficacy is perhaps an unavoidable illusion, but it is an illusion. Somehow, because of their history, and their place in the stream of physical causes, bodies do what they do, and so-called minds follow along, constructing reasons to explain why we did what we were preordained to do.

Some dualists say that this would make people effectively robots, and we can’t really imagine that people are robots—as opposed to observing that sometimes people act robotically. People don’t always act freely, but to be people they must have the general capacity to do so. But what does it mean to say that people who think they can imagine something, like people being robots, really can’t imagine it? What is really imaginable? How does imagination affect what’s real? Quantum mechanics seems in some respects contradictory—does this make the reality it “describes” unimaginable, even as its mathematical formulas produce correct predictions? Is this a false analogy?

This is one way the debate between monists and dualists takes shape. How can we see more clearly what the issue is, where the disagreement lies? What difference does it make? Why should we accept either one of these beliefs, and what are the consequences if we do? Is there a middle ground?