What are you?

Dr Ben Holloway, Professor of Philosophy and History of Ideas, Southeastern Baptist Theological Seminary

There are many questions you could ask about yourself. Not all of them are philosophical. Whether you are human can be decided by considering the scientific evidence for your biological status. DNA is species-specific. Hence, one can determine whether anything is human by examining its DNA. Moreover, you are an individual human. At conception, a newly fertilised egg has a genetic code that is not identical to either its mother or father. It is an individual human being. Determining whether you are dead or alive is also a matter of conducting a series of observational tests for responsiveness, movement, and brain activity.

Whether you are a person is a theological, moral, and legal question. The theological question is answered in Genesis 1:26-27, which tells us that all human beings are made in the image of God. God is paradigmatically personal. He is conscious, rational, capable of deliberating and acting. Since being made in the image of God entails that we are like Him in those ways, human beings obtain a moral and legal status of personhood such that they should not be unjustifiably killed (murdered).

Whether you are a mind or a body, or some combination thereof is a metaphysical question. In what follows, I shall outline two competing views on the subject—dualism and physicalism—and argue that dualism should be preferred.


“I am…only a thinking thing, that is, a mind…I am not the assemblage of members called the human body” (Descartes, Meditation II).

Suppose you discover something that is true of you but not of your body. It would follow that you are not identical to your body. If you aren’t your body or any part of it, what are you?A brain with arms and legs walking down a pavement

Dualists suggest that you are mental in nature. You are a soul. Some dualists argue that you are only your soul, and you have a body. Others suggest that you are essentially your soul. You could exist without your body, though your body is presently part of you.  Still others are inclined to adopt a view according to which a human being is a “single substance with both corporeal and incorporeal activities” (Ed Feser, “Aquinas on the Human Soul,” 96). You are both the bodily material from which you are made and the form which makes you human. In death, one loses bodily powers and properties. But one is still a human being. It is like a very radical amputation, not merely a limb, but the whole body.

All dualists agree that you are not identical to your body. You and your body are not one and the same thing. To be identical to your body entails that there can’t be anything true of you that is not true of it. Analogously, if Jim is identical to Samantha’s father, then there won’t be anything true of Jim that isn’t true of Samantha’s father.

However, the dualist suggests that there are lots of things that are true of you but not your body. For example, when you think that London is the capital of England, you are thinking about London and England. You can think about things, but no physical thing (even a brain or a complex machine) can relate itself in such a way to things in the world. Since you can think about such things, but your body can’t, you are not identical to your body.

Consider the sentence, ‘London is the capital of England.’ You can chop the sentence into parts (L-o-n-d-o-n …) but you cannot chop up the thought that London is the capital of England. If not and, you have the thought, you are not identical to your body.

Consider the physical things you can sense. Sometimes, you can be wrong about them. You think you see a cow, but it turns out to be a plastic representation of a cow. You could be wrong about all physical things. You may just be imagining them. However, you cannot be wrong about your own existence. As Descartes famously demonstrated, any time you doubt your existence, you prove your existence (since a doubting thing must be an existing thing). Thus, you cannot be identical to your body.

Consider the following. You are happily (I presume) reading about mind-body dualism. You are so absorbed in the material that you don’t notice a vast team of nano-surgeons replacing all the parts of your body with replacement parts. If you are identical to your physical parts (or a single part like the brain), then you’d no longer exist. However, it seems plain that you could exist in the new body. After all, over a lifetime you do continue to exist in various ‘new bodies’ as you grow from a child to a man/woman. Therefore, you are not identical with your body.

Dualism also conforms with many of our biblical beliefs about the afterlife. Our bodies may die, but we can go on existing. This could only be the case if we are not identical to our bodies. Hence, dualism conforms with what we know about the afterlife from the Bible.

Some complain that if we are not identical to our bodies, then we would be licensed to think that the body is of no importance. Such a view doesn’t follow from dualism, however. Just because I am not identical to my body, it doesn’t follow that my body is of no importance. For example, the body is important because it is what you use to worship God. It is “for the Lord” (1 Cor 6:13).


There are lots of people who disagree with dualism. For example, reductive physicalists think that mental aspects of human life such as beliefs and desires can be reduced to physical things. There is nothing more to you than your body even though we talk as if there is.

The advantage of physicalism is its simplicity. There is only one kind of thing out of which the universe is made. One doesn’t need to explain anything by appeal to mental objects or their properties.

However, many common ideas about us humans don’t fit with physicalism. Thus, the physicalist must have some means of explaining away common sense beliefs about human persons. The most pressing of which are apparent mental phenomena such as beliefs and desires.

Behaviourists claim that, when we talk about beliefs and desires, we are really talking about behaviours and dispositions to behave. For example, consider the following belief (from Ed Feser, Philosophy of Mind, 62): ‘It is raining outside.’ How could we analyse it solely in terms of behaviour? Perhaps, we might say that the belief that it is raining outside is merely the disposition to get an umbrella and put on a coat.

On this view, beliefs are merely dispositions to behave in some way. A disposition is describable without reference to mental states. A glass is fragile just means that it breaks when struck; it has the disposition to break when struck. Similarly, what we mean by belief is merely a disposition to behave in a certain way.

However, as Ed Feser points out, the behaviourist’s analysis is incomplete. Someone disposed to get an umbrella and put on a coat desires not to get wet. Now the physicalist will have to explain desire in behavioural terms. Even if that were possible, the physicalist would have to do the same with fear since someone who desires not to get wet fears that she will catch a cold if she gets wet. And then someone who fears that she will catch a cold if she gets wet believes that nasty wet weather causes people to catch colds.

This could go on forever. The problem is: the behaviourist must supply an analysis to explain away every mental state. But for every mental state explained away, another one pops up. If mental states pop up forever, then either there is an infinite number of mental states, or mental states are more fundamental than their physicalist explanations. Since it cannot be the case that there are infinite mental states (in a finite human subject), mental states are more fundamental than their physicalist explanations.

An alternative way to explain away mental states is functionalism, according to which, like a computer, our brains compute inputs and produce outputs. For instance, what we call beliefs are just events in which there are causal processes in our brains.

However, the solution doesn’t work. To see why, we’ll perform a thought experiment provided by John Searle. Imagine that you are in a room with a slot open to the outside and a large instruction manual. Through the slot comes a piece of paper upon which is a set of symbols you don’t understand. The instruction manual tells you what symbols to write on the piece of paper in order to respond correctly. You correctly respond to the input, but you did not understand what you wrote. Functionalism describes mental life in such terms, but this is not how you interact with what people say to you nor how you respond to them. Consequentially, functionalism fails.

Another way to be a physicalist is to suggest that we are identical to our brains. For any apparent mental state, all we have is a brain state. The mind-brain identity theory suggests that we have enough information from science to explain all mental phenomena. We know about nervous systems, neurons, and synapses. Surely, if there is more to discover, we will one day have a full description of all the things we take to be non-physical in terms of physical entities and interactions.

At best, the identity theory amounts to a promissory note. We are told that at some point in the future a full and physicalist explanation will be forthcoming. But at the present we have no reason to reject dualism.

We do, however, have some good reasons to reject reductive physicalism.

According to reductive physicalism, to believe something is merely to be in some physical state. Thus, we should eliminate any reference to mental states. According to a Lynn Ruder Baker, to assert something is to express a proposition one believes is true. But then, assertion appears to entail mental things like beliefs.

If reductivists are right, then they must be able to explain the difference between asserting something and doing something else such as lying, acting, or telling a story. The eliminativist cannot do any of these things without appealing to beliefs. Thus, reductive physicalism is false.

Frank Jackson asks us to imagine a scientist who has been forced to study the world from a room which has no colour in it. Everything is black, white, and grey. As a scientist, she can study a red rose and discover everything about it, but she cannot experience its colour. If physicalism is correct, then there is nothing more to knowing the colour red than knowing everything about the colour. Suppose she is let out of the room and is given a red rose. Will she learn anything? It seems she will. She will know what it is like to see red. If so, reductive physicalism is false.

Perhaps, then, there is a way to have one’s cake and eat it. Perhaps there is a way to describe the universe in two ways while holding that reality is only composed of one physical substance.

According to non-reductive physicalists, all that exists is physical. However, a non-reductive physicalist embraces property dualism according to which, the mind and brain are the same thing, but some properties are mental properties, and some properties are physical properties. Mental properties are said to supervene on physical properties. According to this view, mental properties obtain only if certain physical properties are present, and mental and physical properties co-vary such that if there is a change in one, there is necessarily a change in the other.

Arguments against the view exploit a contradiction between the two theses – It cannot be the case both that (i) all non-physical properties depend on physical properties without being reduced to physical properties and (ii) all entities that exist are physical entities.

Jaegwon Kim argues that, given a set of physicalist assumptions, the supervenience of mental properties cannot help but fall foul of one or other physicalist assumptions. Physics is supposed to exhaustively explain all physical events, and, for any event, a single cause is a sufficient explanation. And to keep it simple, any explanation must be the least complicated. Taken together, physicalists have no need for mental explanations. Mental properties lose their explanatory power since one can explain the cause and effect without invoking mental properties at all.

In sum, physicalist views competing with dualism do not fare well and, since dualism is much more compatible with Christian teaching on the afterlife, Christians are usually committed to dualism.

Caring for People

How does such a discussion aid our ministries? Primarily, it helps with how we care for people. When we care for human persons, knowing them better will help. Of course, we have to get to know people personally, but having biological, theological, moral, and metaphysical knowledge of human persons can only help our task.

For example, a counsellor or therapist will care very differently for a thing she thinks is purely physical than one she thinks is mental. Think of caring for a physical mechanism. What kinds of therapy could you offer? Behaviourists focus on conditioning behaviour through repeated exposure to something one fears, disincentivising unwanted behaviour, and breaking and building associations. Often therapeutic language is deeply physicalist. We are mechanisms with ‘behaviours’ that are ‘triggered’ by inputs. To care for a human is to manage physical events by conditioning the mechanism.

Other approaches emphasise beliefs, assuming the mind is more fundamental than the body. By adjusting beliefs, one can produce a cure for what ails the body. But are beliefs changed by conditioning or by reasoning? I can attempt to cause someone to adjust their beliefs, or I can attempt to persuade them with reason. Which route I take depends on what I believe that person is. Are we primarily input-output mechanisms or are we reasoners? Our methods of caring for others will, in part, reflect what we think we are caring for.

Further Reading

Although I have concentrated on the philosophical discussion, whatever conclusion one reaches, it should at least be compatible with what the Bible teaches. For example, since the Bible clearly teaches an afterlife for human beings, any metaphysical theory that rules out life after death should be rejected even if it is a satisfying metaphysical theory. There may also be good confirming evidence for one view over another from the Bible. A good book on the subject is by John Cooper’s Body, Soul, and Life Everlasting.

Many Christian philosophers defend dualism. For example, Alvin Plantinga argues:

“I am not my body, or some part of it such as my brain or a hemisphere or other part of the latter, or an object composed of the same matter as my body (or some part of it) and colocated with it.” (Alvin Plantinga, “Materialism and Christian Belief”, 99, 102).

There are some exceptions. Kevin Corcoran attempts to defend a Christian version of physicalism in his book, Rethinking Human Nature: A Christian Materialist Alternative to the Soul.

For some Christian philosophers, conclusions from the philosophy of mind offer additional evidence for the existence of God. See, for example, J.P. Moreland’s, Consciousness and the Existence of God.

There are lots of good introductions to the philosophy of mind. I particularly like the easy-to-read introduction by Pete Mandik, This is Philosophy of Mind. Others worth a look are Jaworski, Philosophy of Mind) and Ed Feser’s, Philosophy of Mind.

Lynn Ruder Baker’s arguments against physicalism can be found in her 1987 work, Saving Belief: A Critique of Physicalism. Frank Jackson’s argument against reductive physicalism is in his 1982 article, “Epiphenomenal Qualia.” For criticisms of property dualism see Jaegwon Kim, Physicalism, or Something Near Enough. John Searle’s argument against functionalism can be found in his 1980 article, “Minds, Brains and Programs.”

I also began with biology, theology, and ethics. You can find a defence of the views I espoused in the section on abortion in John Feinberg and Paul Feinberg’s Ethics for Brave New World. Their recursive definition of person is particularly valuable.