Philosophers has been argued for some centuries now whether minds really do act on the organisms, or whether organisms do act on the minds. Are mind and body two distinct things or they take part of the same realm?

I. Dualistic Interactionism

Dualistic interactionism is the position that there are mental phenomena distinct from, and irreducible to, physical features of the human body. These two realms causally interact.

Arguments for dualistic interactionism

(1) New sensation argument (body > mind)

I felt cold and I came out with an idea that winter is coming. Hence, body can affect mind.

(2) Books & Bridges Argument (mind > body)

We built the bridge. We infer that mind is responsible for the bridge to be built. The mind is playing a causal role here.

Broad’s response: In reality, brain state causes mental events, but we infer that mind is responsible for the brain state change. The mind is nowhere because he does not exist in space.

(3) Evolution argument

Mind does not make any difference at all to survival and reproduction. Mind is not the product of evolution processes. Hence, mind is distinct from body. Once you got immaterial stuff and it exists, and material stuff and it exists, then there is a causal connection between them.

Objection: It’s not clear what evolutionary story we can get from that. This argument is not clear.

(4) Telegram Argument

Mind is sitting in a hole in the brain surrounding by telephones.

  1. If there is an interaction, then there is a hole in the brain. P → Q
  2. There is no hole ∼ Q
    ∴ Therefore, there is no interaction. ∼ P

Broad’s response: this argument presupposes that mind is located somewhere, but he is nowhere.

Arguments against dualistic interactionism

The following are philosophical arguments.

(1) Unlikeness Argument

Mental phenomena and physical phenomena are radically different. If causality is an interaction of two items of the same type, then dualistic interactionism does not make sense.

Broad’s response:
You cannot think of material and mental stuff as two different objects. You cannot observe mind since it is nowhere. Yet, volition and voluntarily movements can be causally connected. For instance, when I pin my arm, it causes pain.

(2) Binding Whole Argument

There has to be a binding whole so that two things could interact. All physical events are related to the extended whole, but mental events are not like that.

Broad’s response: Even though mental and physical wholes are distinct, there is an interaction between them through the third whole. Sometimes, there should be some other conditions applied. Volition is not sufficient, but a necessary condition.

(3) Hume’s argument from Ignorance

Hume says that the connection between bodily movements and mental movements is mysterious. There might be some constant conjunction between the mental and physical event.

Broad’s response: It’s not mysterious. When I have desire to pick up a piece of chalk, I do. Without desire, this wouldn’t happen. I sense that there is a causal connection when I pick up a piece of chalk. There would not be voluntarily actions if mind would do independently from body. So, to have free will, we need causal interaction.

The following are scientific arguments.

(4) Argument from energy

If there is an interaction between mind and body, there would be a transfer of energy from mind to body or from body to mind.

Broad’s response: Mind does not have to transfer energy to the body. Taking the case of a weigh swinging at the end of a string hung from a fixed point, we can say that the mind could affect the body just as the string affects the ball. Even though there is no a transfer of energy from the string to the ball, the string affects the ball.

(5) Argument from nervous system

Deliberate action is the same sort of thing as reflex. It is just more complex.

Broad’s response: There is a difference between reflex action and voluntary action.

II. Reductive and Nonreductive Materialism

Reductive materialism holds that there is nothing in the world over and above the entities postulated by physics. Smart, as one of the defenders of materialism and scientific realism, argues that electrons, micro particles, and energy exist, while mind doesn’t. Consequently, there are no nonphysical items and no causal interaction between mind and brain. Sense experience, thoughts, dreams and the like are nothing but physical motion within the human body. Mental states are just our brain states, since there is only one physical realm.

Similarly to reductive materialism, Cornman’s nonreductive theory rejects psychophysical dualism and defends the monistic thesis. According to such a theory, every mental state is identical with the brain one. On the other hand, these entities are neutral in a sense that they are neither purely physical nor purely mental. Even though there is only one physical stuff, some of the physical properties may give rise to psychological properties. Hence, unlike reductive materialism, the neutral identity theory allows mental phenomena such as the pain of a headache or the perceived redness of the flag of China.

Cornman’s objection to reductive materialism

Cornman argues that though reductive materialism offers us a simple and rational solution for the mind-body problem, it is false because of the existence of qualia. In other words, there are some individual instances of subjective, conscious experiences that reductive materialism ignores. We experience those intense, stabbing, and throbbing pains that are quite distinct from the physical phenomena. These properties are not something we would discover in the brain, so pain is real. This is also true of other sensations and seeing things as they seem, e.g. “whiteness”. There is something metaphysically real about “whiteness” that can not be reduced to nerve impulses and molecular activity. If it is not just the brain state, then it is false that all mental phenomena are nothing but physical phenomena. Smart, however, would argue that “whiteness” does not exist in the mind. When I am appeared to whity, I got the sense-data of whie, but it is not real. This experience is reduced to the brain state. We can’t make any sense of immaterial stuff interacting with physical stuff.

Cornman’s objection to epiphenomenalism

Cornman objects also to other alternative theories of mind-body problem such as epiphenomentalism and dualistic interactionism. Epiphenomenalism postulates mental entities as by-products of physical processes. Consequently, there are two distinct realms. There are no causal laws between physical events and mental events. Although epiphenomenalism suits Darwinian theory of evolution and successfully explains the behavior of human beings by a one-sided action, it does not avoid two serious objections. The first one relates to the volition that epiphenomenalism fails to explain. When I raise my arm, it is dubious that brain acts on the mind to generate the order for itself. Hence, I am not responsible for my actions, for it is the brain that generates my volition. In addition, epiphenomenalism assumes that there is one extra physical law that connects physical events with mental events. It is a confusion for science, since there is no scientific explanation of mental phenomena that constitutes a totally different realm.

Cornman’s objection to dualistic interactionism

Similarly to epiphenomenalism, dualistic interactionism fails because it does not fit the scientific picture. If mental phenomenon is irreducible to physical features of the human body, then how can we explain that mind can cause a physical realm? When I have a particular volition to move the book on the table, volition can be brought by mind, but mind is not a physical phenomenon, since it is nowhere. Even if mental event could causally affect something that is physical, dualistic interactionism is implausible, since it violates the principles of the conservation of mass-energy and of linear-momentum. For instance, dualists argue that mental phenomena change the total linear-momentum within the brain by affecting the synapses. Yet, there are only two way for that to happen. There has to be electromagnetic force or mass, which mind does not have in any case. So, brain does not act in accordance with volition and mind does not affect brain. Therefore, Cornman rejects the interaction theory along with epiphenomenalism.

Objections to Cornman’s nonreductive theory

Cornman concludes that we need to accept the neutral identity theory that gets around all of these objections to reductive materialism, epiphenomenalism, and dualistic interactionism. While his nonreductive theory takes the best of the reductive materialism and avoids the problem of the qualia’s experience, there are some objections to his view. First, contemporary linguistic philosophers would claim that nonreductive materialism invokes meaningless sentences such as “my nerve fibers are aching”. However, Cornman easily refutes this argument by comparing the liquid pool of water with the bunch of particles. It also sounds odd, but we have become accustomed to such statements. Another objection is based on the assumption that if the neutral theory is true, then it is odd that only certain groups of molecules in only certain brains of only certain animals have psychological properties. Cornman argues that it is not implausible to think that the human brain is unique in its structure and constituents that allow for psychological properties to emerge. For instance, we admit that certain systems of molecules have the properties of salt, but he constituents of these systems do not have any properties individually. The last group of objections addresses extrasensory perception and communication with the dead. Opponents to neutral identity theory claim that there is mental telepathy that proves the existence of mental phenomena distinct from bodies. If the communication among human beings without reliance on any sense organs were true, it would fail under pressure of the same objections to dualistic interactionism. Similarly, such experiences as communication with the dead lack sufficient evidence and do not fit the principle of the conservation of liniar-momentum. However, nonreductive materialism would be compatible with these experiences if it would be the case of hallucination that emerges from physical properties.

Conclusion

In conclusion, I agree with Cornman that nonreductive materialism has more to offer than reductive materialism. It makes sense of mental events that reductive materialism fails to explain. Although Cornman does not give us a detailed explanation of how emergents arise from physical events or what kind of groups of molecules might be responsible for this process, it is rather the question of further observation and experimentation by methods that are compatible with those that scientists actually use. Moreover, the neutral identity theory avoids so far a serious objection. Therefore, we probably should adopt it as the most appealing solution of the traditional problem of mind and body.

Bibliography:

  • Broad, C.D. The traditional Problem of Body and Mind, in Reality in Focus: contemporary readings on metaphysics / edited by Paul K. Moser, Prentice-Hall, Inc, 1990
  • Cornman, James W. Mind-Body Identity, Privacy, and Categories, in Reality in Focus: contemporary readings on metaphysics / edited by Paul K. Moser, Prentice-Hall, Inc, 1990
  • Smart, J.J. C. Materialism, in Reality in Focus: contemporary readings on metaphysics / edited by Paul K. Moser, Prentice-Hall, Inc, 1990