BOOK SYMPOSIUM PRÉCIS OF MIND, BRAIN, AND FREE WILL by RICHARD SWINBURNE University of Oxford This book is a defence of substance dualism (that we human beings consist of two parts, body – a contingent part, and soul -the one essential part), and of libertarian free will (that we are not always fully caused to form our intentions), from which it follows that we are often morally responsible for our actions. But in order to establish these points I need to introduce some crucial terminology, and to defend some general theories of metaphysics and epistemology. So in chapter 1 I distinguish three kinds of thing: substances (the constituents of the world such as electrons, planets, and houses), their properties (such as weighing 1000kg, or being spherical), and events (occurrences at particular times, which consist in substances having or changing their properties); and I argue that the history of the world (in an objective sense) just is all the events that happen. In order to tell that history we must pick out substances, etc., by what I call their 'informative designators', which (roughly) are rigid designators such that if someone knows what the word means, they will know the necessary and sufficient conditions for its application. Thus 'red' is an informative (rigid) designator, but 'water' as used in the eighteenth century is an uninformative designator, because speakers then did not know the essence of water. We should count two substances (or whatever) the same substance (or whatever) iff their informative designators are logically equivalent. Then a proposition is metaphysically necessary/ EUROPEAN JOURNAL FOR PHILOSOPHY OF RELIGION 6/2 (SUMMER 2014), PP. 1-3 2 RICHARD SWINBURNE possible/impossible iff it is logically necessary/possible/impossible when we substitute coreferring informative designators for any uninformative designators. In chapter 2 I consider what makes a belief that a certain event occurred or that a certain scientific theory is true, or that some assertion is possibly true, a justified belief in the sense of a belief which is probably true on the evidence available to the believer. I defend the principle of credulity, that every basic belief is probably true in the absence of contrary evidence (that is, a defeater); and I apply it to the justification of our beliefs about logical modalities, our beliefs resulting from experience, memory, and testimony, and our beliefs about the probable truth of scientific theories. I claim that it is a defeater to any belief resulting from experience, memory, or testimony that the event purportedly experienced, remembered or testified to did not cause the resulting belief. I then apply these results in chapters 3 to 7, to examine the relation of our life of thought and feeling to what happens in our brains and so in our bodies. I argue in chapter 3 that there are two kinds of event in the world: physical events (including brain events) and mental events. Mental events are events to which the subject (the person whose events they are) has privileged access, that is a way of knowing about them not available to others. Among mental events are pure mental events, ones which do not include any physical event. Among these are beliefs, thoughts, intentions, desires and sensations, events of which the subject is often conscious and which are then conscious events. Given that events are individuated by informative designators, it then follows that pure mental events are not the same as physical events and do not (metaphysically) supervene on them. I go on in Chapter 4 to argue that not merely do brain events often cause mental events, but mental events (and in particular intentions) often cause brain events, and thereby bodily movements. Many neuroscientists have interpreted the results of recent neuroscientific experiments as showing that our pure mental events (and in particular our intentions) never cause brain events. I argue that these results do not show that, and that no experimental evidence of any kind could possibly show that, because in order to show that we would need evidence about our pure mental events which – given the principles about memory and testimony cited above – could only be obtained on the assumption that those events do cause brain events. In chapter 5 I argue that this result that our intentions often cause our brain events needs to be expressed more carefully as the result that 3PRÉCIS persons often cause brain events when they intentionally cause bodily movements. The view deriving from Hume holds that the causes of events are other events, logically distinct from them; for example that when the ignition of dynamite causes an explosion, the ignition is a separate event from the explosion, and the first event causing the second one consists in there being a law of nature (a consequence of fundamental laws) which determines that an event of the first kind is followed by an event of the second kind. I now argue that whatever might be the case with non-intentional causation (e.g. the ignition of gunpowder causing an explosion, or a brain event causing pain), in intentional causation the cause is the person whose intention it is, a substance and not an event. A person having an intention (in acting) is simply that person intentionally exercising causal power. In chapter 6 I move on to the issue of the nature of the substance, the human person to whom pure mental events (including intentions) belong. I argue that each human person can pick out themselves by an informative designator (e.g., 'I'), whereas others can only pick out a person by an uninformative designator – since each of us knows the necessary and sufficient conditions for being who we are, and others do not. Hence since it is logically possible that I should exist without a body, it is also metaphysically possible. Each of us is a pure mental substance, having a soul as their one essential part and a body as a non-essential part; physical properties belong to us in virtue of belonging to our bodies, and pure mental properties belong to us in virtue of belonging to our souls. Given that human persons cause brain events, the next issue is whether humans are always fully caused to cause the brain events they often do cause (and so the resulting bodily movements) by earlier brain events or mental events. I argue in Chapter 7 that it is most improbable that it could be shown that we are always so caused – since any purported laws of mind/brain interaction would be so complicated that it would be almost impossible to get enough evidence to establish or refute them. Hence when it seems to us that we are causing our bodily movements (and so the brain events which cause them) without being fully caused to do so, we should – by the principle of credulity – believe that that is how it is, and so that we have (in this crucial sense) free will. I then proceed to argue in Chapter 8 that, given that that is our situation, we are morally responsible for our actions – guilty and deserving blame for doing what we believe wrong, meritorious and deserving praise for doing what we believe to be good actions beyond obligation.