Mind, Morality and Free Will
Oxford University Press
1) Mental and Physical Properties
A shorter version of this review will be available on www.apologetics315.com
Theologians and scientists seem blissfully unaware that that the soul is alive and well in contemporary philosophy. JP Moreland, Dean Zimmerman, William Hasker, Charles Taliaferro, Stuart Goetz, Robin Collins and Alvin Plantinga have all produced novel and rigorous arguments in defence of dualism – that you are an immaterial self and not identical to your body. This must be gratifying for Richard Swinburne, who swam against the tide of philosophical fashion in 1986 with The Evolution of the Soul. Mind, Brain and Free Will updates his arguments for dualism. The book is refreshingly clear, rigorously argued and a joy to read.
Swinburne argues that physical events and conscious events – beliefs, desires, thoughts, purposes and sensations – are not identical. To put that another way, the terms we use to pick out physical events, and the terms we use to pick out mental events, never refer to the same thing. We need to think a little about words and concepts here – after all, we cannot say much about the world without them! Anyone who knows what terms like “red” or “pain” mean knows how to use them. They know exactly what it is to have a sensation of red or a pain. They know when and how to apply the terms, and can make simple inferences using them . (For example we can infer “it is a sensation” and “it is unpleasant” from “it is a pain.”)
To describe the world as accurately as possible we terms like “red” and “pain” because they get beyond superficial appearances. Swinburne calls these “informative (rigid) designators”. A rigid designator always designates the same object in every conceivable circumstance (for example, “David Cameron” refers to the person who is currently Prime Minister, and would have done so if he was not Prime Minister. “Prime Minister” does not rigidly designate the same person, because different people occupy that post at different times.) If a competent language user knows what is involved in the application of a rigid designator – if they know the set of necessary and sufficient conditions for a thing to be that thing – then that designator is an “informative rigid designator.”
Some terms, however, do not get at the essence of what they designate; we don’t fully understand what is involved in their application. Early explorers could see a mountain from Tibet which they identified by its shape and called “Everest”. At the same time, other explorers in Nepal could see a mountain with a different shape which they called “Gaurisanker”. However, it soon became apparent that the two mountains were identical – it was the same mountain viewed from different perspectives. “Gaurisanker” and “Everest” actually referred to the same rocky matter. Of course, this did not surprise early geographers – after all, they were only referring to superficial appearances, and not what underlay those appearances.
Two properties, or events or substances, will be identical if their informative rigid designators are logically equivalent (if each entails the other). So, for example, if a shape is trilateral it is also triangular. Being a rectilinear closed figure with three sides entails having three, and only three, angles. Obviously, there are certain things that simply could not be identical. For example, explorers could never discover that the Nile and Everest referred to the same geographical objects. It is also clear that mental properties and physical properties are not identical. “Reflecting light at such and such a wavelength” does not entail “red” or “blue” – that is, it does not logically entail how that reflected light will appear to observers.
Mental and Physical Properties
Suppose I put my hand too close to a flame and receive a burn. I feel pain, referring to a particular unpleasant sensation. Such a feeling is uniform and simple, and it impresses itself directly on my consciousness. Observers could infer that I was in pain from my behaviour. However, I don’t need to infer that I am in pain by observing my behaviour or brain states; I feel it directly. As Swinburne puts it, I have privileged access to mental events like pain. It is this mental property that I refer to when I say I feel “pain”. I am picking out an experience, describing the property as it appears “on the surface.” I am not picking out a physical event which causes that experience.
The criteria for being a “pain” and for being its underlying brain state are different. We know what the term “pain” refers to without any knowledge of the underlying brain state. “Pain” refers to a specific, simple sensation. The physical events associated with pain are anything but simple. If I describe the complex sequence of neurological events that accompanies that pain, and the specific function that the pain plays in moving my body away from harm, and even the set of physical events that the pain “represents”, I leave something important out: that simple, specific sensation that makes pain what it is.
We can informatively designate the feelings of pain and heat without knowing anything about physics or biology. We can also informatively designate behaviour and brain states without knowing anything about the accompanying sensations (we do not know “what it is like” for rodents to feel fear or for sea snails to feel pain). It follows that mental states and physical states are not identical. It also seems that mental states do not necessitate particular physical states. There seems to be no reason to believe that a being with a different neuro-physiology or neuro-anatomy – like an artificially intelligent robot, or a silicon-based life form – could not feel sensations like pain.
Some properties of physical objects are entailed by their underlying physical structure. In these cases we can see how the properties of the whole follow from the properties of the parts. So if we had sufficient knowledge of its chemical structure and the underlying physics, we could predict that frozen water would float on liquid water. But nothing about a brain’s underlying physical properties seems to entail a particular conscious experience. In fact, the underlying physical structure of our bodies does not entail that we should feel anything at all. There is absolutely nothing about the interaction of physical parts that would allow us to predict the emergence or character of a conscious experience.
Very roughly, mental properties would supervene of physical properties if for any mental property like joy, if a person has joy, there is a physical property (like a brain state), such that the person with joy has that physical property, and whoever else has that physical property has joy. But it is surely conceivable that a person might lack the experience of joy even though they have the same brain state as others who experience joy; it is even conceivable non-physical beings exist and experience joy! We can’t rule such things out a priori; they are not logically impossible! So, if a mental property does not logically entail a particular physical property, and if there is nothing about a physical property that entails a particular mental property, mental states do not supervene on physical states.
The point is that Mind simply cannot be located in the natural world. Some have argued that consciousness emerges from our brains, like photosynthesis emerges from the plant’s interaction with its environment or digestion emerges from the intestines and stomach. The problem is that these are physically complex events: and once you understand various biological structures in the human body you understand digestion. But conscious experience cannot be broken down into compositional, spatial parts. And, as we have said, nothing about the anatomy of the brain would allow us to predict the emergence of conscious states. So the mind is not identical with a physical process.
Nor can physicalists retreat to “functionalism” to account for consciousness. “Functionalists” identify pure mental properties with events that have functions in a person’s life or behavior and which tend to have certain kinds of causes and effects. Swinburne gives a (highly simplified) illustration of a functionalist analysis of pain. To a functionalist, “the property of having a pain is the property which events have if they tend to be caused by bodily damage …and tend to cause crying-out or wincing and a desire for bodily damage to cease. And the property to have a desire to do A is the property which events tend to have if they are caused in certain standard ways and tend to produce and intention to do A.”
Swinburne notes what the functionalist account leaves out – what pain actually feels like. We can only discover the events that tend to cause pain, or that tend to be caused by pain, if we have some prior understanding of what pain is! We must have privileged access to a pure mental event before we can discover and understand the more complex circumstances in which it occurs. Only then can we can give a definition of the causes of mental events like pain.
Swinburne also argues that mental events cause physical events. That is, our beliefs, purposes and sensations can act on the brain to cause us to take action. It would be odd if conscious events were caused by the brain but conscious events could not cause brain events. Yet some theorists are keen to assert this because they assume that the physical universe is a “closed causal system”. They argue that science assumes physical events can only have physical causes. Some appeal to the “principle of the conservation of energy” to argue that (1) any causal interaction involves an exchange of energy and (2) the rate of change of total energy in a closed region of space is equal to the total rate of energy flowing through the spatial boundary of that region. In other words, energy only changes in one region if there is a change in a neighbouring region.
However, Swinburne argues that since the revolution of Quantum Mechanics, the physical principles of classical mechanics (like the principle of the conservation of energy) only hold as statistical generalizations. Small amounts of energy can be gained or lost in short periods of time. Furthermore the EPR correlation, where measurements carried out using one detector can simultaneously affect the results of measurements carried out using a distant detector, suggests that causal influences can take place without any energy-momentum exchange. Physics is not a good refuge for those who believe the universe is a closed causal system. But perhaps they could argue that scientists must assume causal closure in their experiments. As Stuart Goetz explains:
“For example, in his pioneering work on the brain Wilder Penfield produced movements in the limbs of patients by stimulating their cortical motor areas with an electrode. As Penfield observed the neural impulses that resulted from stimulation by the electrode, he had to assume during his experiments that the areas of the brains of his patients on whom he was doing his scientific work were causally closed to other causal influences. Without this methodological assumption, he could not conclude both that it was the electrode (as opposed, say, to something ‘behind the scene’ such as an empirically undetectable human soul, either that of the patient or someone else, or God) that causally affected the capacities of the neurons to conduct electrical impulses, and that it was the causal impulses of those neurons that causally affected the same capacities of other neurons further down the causal chains to produce the movements of the limbs.”[i]
However, it does not follow that causal closure applies to the entire universe all the time. In fact, Swinburne points out that a scientist would face insuperable obstacles in establishing Causal Closure through experimentation. An experiment could be designed to show when certain conscious events occur relative to certain sequences of brain events. If Causal Closure is true, whether or not some conscious event occurs at the beginning of a sequence of brain events will not affect whether or not the sequence is completed. So, once the series of brain events that leads (say) to a subject tapping a button begins, the lack of conscious awareness of a decision to tap a button at the beginning of that sequence will make no difference over whether or not a subject taps a button.[ii]
If this prediction were confirmed for a large random sample of subjects, Causal Closure would be confirmed. However, how can the scientist find out if the prediction has been confirmed? Discovering the brain events is one thing; but how does one detect a mental event if it is not identical to a physical event? In this case, the scientist must rely on the testimony of the subjects. The subjects must report when they became conscious of a decision to press the button. If their testimony is to be considered reliable we must assume that the subjects believe that the event occurred at a certain time and intend to tell the truth.
These mental events (the belief and the intention to tell the truth) must cause the brain, and thereby the body, to give the report. But if Causal Closure is true no mental event causes the brain to do anything! Causal closure can only be confirmed by testimony that we must believe is false if Causal Closure is true! Every inference from behaviour to a mental event assumes that the mental can cause the physical.
So, as Swinburne points out, scientists must often assume that the physical realm is not closed. For example, if I report a memory or emotion to a psychologist, they must assume that my experience is a necessary part of the cause of my report. If the psychologist assumes causal closure, and given that mental events are not identical to physical events, they must assume that my report has been caused by physical processes in my brain, and that my experience played no role in my report.
Given that brain states and mental states are not identical, the testimony of subjects would be undermined if scientists assumed that mental properties did not have any causal power. So anyone recording the testimony of a conscious rational subject must assume that the physical world is not causally closed. In fact, because science is a communal project, and because researchers must collaborate to make progress, scientists must assume that the testimony of other scientists has been caused by mental events like beliefs and the intention to report those beliefs accurately. If mental events have no role in causing the testimony of others the rationality of the scientific enterprise is undermined.
So it seems clear that mental properties and physical properties are not identical, and that mental events cause physical events.
Swinburne is, quite rightly, unimpressed with attempts to escape a dualism of mental and physical properties which argue that we merely access one event by two different “modes of presentation”. For example, some suggest that red can be presented as a visible colour and a reflected wavelength. But these “modes” would be real characteristics, like properties. So what advantage do we gain by adding “modes of presentation” to our ontology?
Swinburne also argues for “substance dualism” – the unfashionable view that human beings are immaterial souls or minds. The basis for substance dualism is surprisingly clear. Sometimes conscious events overlap. Consider the experience of being burned by a flame. If it is possible to experience heat, light and pain simultaneously, one subject must experience all three sensations. Furthermore, this one subject must persist through time. I can feel a pain that lasts for one second, and hear a noise that commences 0.5 seconds after I first felt the pain. This noise might continue for ten seconds, but overlap with an experience of a taste that endures for the last five seconds of the noise. Swinburne argues that “[w]hen two conscious events overlap, they are events of the same substance; the overlap entails this.”
David Hume famously claimed that we have no idea of the self because, when we introspect, we do not have an impression of the self. All we find are perceptions and sensations. Hume claims “I never find myself at any time without a perception”. Hume was correct. We never experience “ourselves” unless we are experiencing some conscious event or other. But that does not imply that all I can experience is disconnected conscious events! What I am aware of are numerous conscious events experienced in a common subject – me! I experience and think about everything from one point of view – my own.
To suggest that I cease to exist when I am not experiencing a mental event implies that different substances cease to exist and come into being every time I lose and gain consciousness. It is simpler to believe that one subject endures through such changes. Indeed, we seem to have a vast number of non-conscious beliefs and desires which are connected to each other in rational ways. We do not express all our knowledge in conscious thoughts when we make inferences. Yet most of our inferences depend on numerous background beliefs about the world. We also, as many psychologists confirm, have many non-conscious desires which cause us to act.
We can “look in” on these beliefs – bring them to conscious awareness – and this “privileged access” marks them as mental properties. So, provided we allow that thinking includes these non-conscious beliefs and desires, a mind, or soul just is thinking. This is what endures throughout our existence. It is logically possible that we could have had different bodies or mental events, so this simple self is essentially who and what we are. This self can operate properly only by interacting with a brain –so, in one sense, that is where we are located. Yet we are not aware of the self operating on the brain; we are aware of it interacting with the body. So it seems more natural to think of ourselves as located in a body. This is the part of the world which we are most aware of and which we can, in part, control.
Swinburne argues that “it is an unavoidable datum of experience” that we are immaterial selves who exercise causal influence on our bodies. He also argues that there is a fundamental epistemic Principle of Credulity foundational to all inquiry. In the absence of counter-evidence, we should believe that things probably are the way they seem to be. We seem to be immaterial selves that causally interact with material bodies. Our theories about reality should be tested by experience. We should not begin with our theories and reject experiences that do not fit – unlike contemporary physicalists.
The Principle of Credulity simply states that we should believe that things are as they seem unless we have good evidence that they are not. If we can find no good reason to doubt that things are as they seem then we should accept it is probably so. Swinburne is not suggesting that we naively accept that the world is as it appears. A rational person critically examines the world; she does not assume that the world always is as it appears, so she is open to evidence that things are not as they seem. In so doing, she moves from appearances to the truth. However, every inquiry has to start with some set of data, and has to assume some point of view.
If we cannot start our quest for truth by assuming that most of our ordinary beliefs – about the immediate past, our physical surroundings, the testimony of our neighbours – are probably true, we cannot start at all. Moreover, we cannot choose our beliefs at will, and we cannot force ourselves to believe that our most basic beliefs are false. With the principle of credulity, Swinburne is joining a philosophical tradition that goes back to Aristotle. Furthermore, science builds on this tradition. Scientists test theories by observation and measurement, and science is a communal project, each scientist relying on the findings of other researchers. The scientific enterprise collapses into a sceptical morass if we cannot believe what we observe and if we cannot trust what others tell us.
In The Existence of God Swinburne argued that the existence of consciousness provides evidence for God’s existence. It seems to me that the discussion in Mind, Brain and Free Will certainly gives reason to prefer Theism to Physicalism. If physicalism is true, physics should have the potential to give us a complete description of reality. (The laws of genetics and natural selection will follow from the fundamental laws of physics and the initial state of our universe.) Physics describes a universe with ultimate and irreducible properties of things, like charge, mass, charge, motion and spin, which are governed by mathematical laws.
But conscious states like “awareness” and “aboutness” are not the kinds of state that are described by physics. They arrive too late in the history of the universe to be fundamental; furthermore, it is impossible to see how they could be described mathematically. It is difficult enough to describe a specific feeling of “misery”, or “ecstasy” in poetry or painting. While the associated brain state can be measured in mathematical terms, the phenomenal feeling cannot. Physicalism cannot account for conscious states, whereas Theism, with its commitment to a personal creator, has no difficulty in explaining conscious experience.
As I read his thoughts on moral responsibility, I wondered if Swinburne’s apologetic could be strengthened by arguing that certain moral objective truths are only explicable if theism is true. In Mind, Brain and Free Will he maintains that we do not need theism to explain objective moral facts because it is a logically necessary truth that moral properties supervene on non-moral properties. So “our concept of the moral is such that there is no world W in which a is wrong and world W* exactly the same as W except that in W* a is (overall) good. It follows that there are metaphysically necessary truths of the form ‘If an action has the non-moral properties A, B, and C, it is morally good”.
However, wouldn’t God’s existence be a fact on which many important moral truths would supervene? Consider the moral value of the individual human. If God created humans in his image, and has a purpose for each human, then it is entailed that every individual human being has immense objective value. Humans lack the same value in an atheistic universe – where each human life is ephemeral and the human race is the contingent outcome of a meaningless, impersonal process. It is true that feelings of sympathy and compassion will have some utility. Perhaps evolution would hardwire such feelings into humans. But this could merely be the illusion of objective moral value.
Furthermore, Swinburne’s discussion of “informative rigid designators” could be extended to illuminate the relationship between “God” and “the Good”. It is entirely possible that the terms “God” and “the Good” refer to the same object; that when we talk about what is ultimately Good we are referring to God’s nature. God shares many of the properties that we would associate with the ultimate Good. He is perfect, free from defect, and this is the state that every rational being would value and desire. Evil is irrational and destructive; God, as the rational creator, is evil’s polar opposite. Being God would entail being the source of all goodness. A world without God would be a world without objective moral value.
Other things would be good insofar as they resembled God or what God would value. So it would make no more sense to ask “is something good because it is desired by God, or is it desired by God because it is good?” than to ask “is a shape triangular because it has three sides, or does it have three sides because it is triangular?” To be “desired by the perfectly rational source of all being” simply illuminates what it means to be “good.” Both phrases pick out the same property. So much for the Euthyphro Problem.
Still, Swinburne has provided a remarkably convincing case for the existence of the soul and the inadequacy of scientism and physicalism. He does not rely on thought experiments, but rather on a rigorous and enlightening discussion of metaphysics and language. His discussion of free-will and agent causation should challenge theological and scientific determinists – a subject that I might return to on another occasion. For now, let me commend the most helpful and convincing book that I have read on the philosophy of mind.
[ii] The famous Libet experiment is discussed in some detail in the text. However, a good summary of the relevant science can be found http://www.bethinking.org/science-christianity/advanced/the-libet-experiment-and-its-implications-for-conscious-will.htm