The pattern of argument is one much used in science, history, and all other fields of human inquiry. A detective, for example, finds various clues-John's fingerprints on a burgled safe, John having a lot of money hidden in his house, John being seen near the scene of the burglary at the time when it was committed. He then suggests that these various clues, although they just might have other explanations, are not in general to be expected unless John had robbed the safe. That each clue is some evidence that he did rob the safe, confirms the hypothesis that John robbed the safe; and the evidence is cumulative- when put together it makes the hypothesis probable.
Let us call arguments of this kind arguments to a good explanation. Scientists use this pattern of argument to argue to the existence of unobservable entities as causes of the phenomena which they observe. For example, at the beginning of the nineteenth century, scientists observed many varied phenomena of chemical interaction, such as that substances combine in fixed ratios by weight to form new substances (for example, hydrogen and oxygen always form water in a ratio by weight of 1:8). They then claimed that these phenomena would be expected if there existed a hundred or so different kinds of atom, particles far too small to be seen, which combined and recombined in certain simple ways. In their turn physicists postulated electrons, protons, and neutrons and other particles in order to account for the behavior of the atoms, as well as for larger-scale observable phenomena; and now postulate quarks in order to explain the behavior of protons, neutrons, and most other particles.
To be good arguments (that is, to provide evidence for their hypothesis), arguments of this kind must satisfy three criteria. First, the phenomena which they cite as evidence must not be very likely to occur in the normal course of things. We saw in the burglary example how the various clues, such as John's fingerprints on the safe, were not much to be expected in the normal course of things. Secondly, the phenomena must be much more to be expected if the hypothesis is true. If John did rob the safe it is quite likely that his fingerprints would be found on it. Thirdly, the hypothesis must be simple. That is, it must postulate the existence and operation of few entities, few kinds of entities, with few easily describable properties behaving in mathematically simple kinds of way. We could always postulate many new entities with complicated properties to explain anything which we find. But our hypothesis will only be supported by the evidence if it postulates few entities, which lead us to expect the diverse phenomena which form the evidence. Thus in the detective story example we could suggest that Brown planted John's fingerprints on the safe, Smith dressed up to look like John at the scene of the crime, and without any collusion with the others Robinson hid the money in John's flat. This new hypothesis would lead us to expect the phenomena which we find just as well as does the hypothesis that John robbed the safe. But the latter hypothesis is supported by the evidence whereas the former is not. And this is because the hypothesis that John robbed the safe postulates one object-John-doing one deed -robbing the safe-which leads us to expect the several phenomena which we find. Scientists always postulate as few new entities (for example, subatomic particles) as are needed to lead us to expect to find the phenomena which we observe; and they postulate that those entities do not behave erratically (behave one way one day, and a different way the next day) but that they behave in accordance with as simple and smooth a mathematical law as is compatible with what is observed. There is an old Latin saying, simplex sigillum veri, "The simple is the sign of the true." To be rendered probable by evidence, hypotheses must be simple.
My next phenomenon is the operation of the most general laws of nature, that is, the orderliness of nature in conforming to very general laws. What exactly these laws are science may not yet have discovered-perhaps they are the field equations of Einstein's General Theory of Relativity, or perhaps there are some yet more fundamental laws. Now science can explain why one law operates in some narrow area, in terms of the operation of a wider law in the particular conditions of that narrow area. Thus it can explain why Galileo's law of fall holds-that small objects near the surface of the Earth fall with a constant acceleration towards the Earth. Galileo's law follows from Newton's laws, given that the Earth is a massive body far from other massive bodies and the objects on its surface are close to it and small in mass in comparison. But what science by its very nature cannot explain is why there are the most general laws of nature that there are; for, ex hypothesi, no wider law can explain their operation.
That there is a Universe and that there are laws of nature are phenomena so general and pervasive that we tend to ignore them. But there might so easily not have been a universe at all, ever. Or the Universe might so easily have been a chaotic mess. That there is an orderly Universe is something very striking, yet beyond the capacity of science ever to explain. Science's inability to explain these things is not a temporary phenomenon, caused by the backwardness of Twentieth Century science. Rather, because of what a scientific explanation is, these things will ever be beyond its capacity to explain. For scientific explanations by their very nature terminate with some ultimate natural law and ultimate arrangement of physical things, and the questions which I am raising are why there are natural laws and physical things at all.
However, there is another kind of explanation of phenomena which we use all the time and which we see as a proper way of explaining phenomena. This is what I call personal explanation. We often explain some phenomenon E as brought about by a person P in order to achieve some purpose or goal G. The present motion of my hand is explained as brought about by me for the purpose of writing a philosophical paper. The cup being on the table is explained by a man having put it there for the purpose of drinking out of it. Yet this is a different way of explaining things from the scientific. Scientific explanation involves laws of nature and previous states of affairs. Personal explanation involves persons and purposes. If we cannot give a scientific explanation of the existence and orderliness of the Universe, perhaps we can give a personal explanation.
But why should we think that the existence and orderliness of the Universe has an explanation at all? We seek for an explanation of all things; but we have seen that we have only reason for supposing that we have found one if the purported explanation is simple, and leads us to expect what we find when that is otherwise not to be expected. The history of science shows that we judge that the complex, miscellaneous, coincidental and diverse needs explaining, and that it is to be explained in terms of something simpler. The motions of the planets (subject to Kepler's laws), the mechanical interactions of bodies on Earth, the behavior of pendula, the motions of tides, the behavior of comets, and so forth formed a pretty miscellaneous set of phenomena. Newton's laws of motion constituted a simple theory which led us to expect these phenomena, and so was judged a true explanation of them. The existence of thousands of different chemical substances combining in different ratios to make other substances was complex. The hypothesis that there were only a hundred or so chemical elements of which the thousands of substances were made was a simple hypothesis which led us to expect the complex phenomenon.
Our Universe is a complex thing. There are lots and lots of separate chunks of it. The chunks have each a different finite and not very natural volume, shape, mass, and so forth-consider the vast diversity of the galaxies, stars and planets, and pebbles on the sea shore. Matter is inert and has no powers which it can choose to exert; it does what it has to do. There is a limited amount of it in any region and it has a limited amount of energy and velocity. There is a complexity, particularity, and finitude about the Universe.
The conformity of objects throughout endless time and space to simple laws is likewise something which cries out for explanation. For let us consider what this amounts to. Laws are not things, independent of material objects. To say that all objects conform to laws is simply to say that they all behave in exactly the same way. To say, for example, that the planets obey Kepler's laws is just to say that each planet at each moment of time has the property of moving in the ways that Kepler's laws state. There is therefore this vast coincidence in the behavioral properties of objects at all times and in all places. If all the coins of some region have the same markings, or all the papers in a room are written in the same handwriting, we seek an explanation in terms of a common source of these coincidences. We should seek a similar explanation for that vast coincidence which we describe as the conformity of objects to laws of nature-for example, the fact that all electrons are produced, attract and repel other particles and combine with them in exactly the same way at each point of endless time and space.
The hypothesis of theism is that the Universe exists because there is a God who keeps it in being and that laws of nature operate because there is a God who brings it about that they do. He brings it about that the laws of nature operate by sustaining in every object in the universe its liability to behave in accord with those laws. He keeps the Universe in being by making the laws such as to conserve the matter of the Universe, that is, by making it the case at each moment that what there was before continues to exist. The hypothesis is a hypothesis that a person brings about these things for some purpose. He acts directly on the Universe, as we act directly on our brains, guiding them to move our limbs (but the Universe is not his body-for he could at any moment destroy it, and act on another universe, or do without a universe). As we have seen, personal explanation and scientific explanation are the two ways we have of explaining the occurrence of phenomena. Since there cannot be a scientific explanation of the existence of the Universe, either there is a personal explanation or there is no explanation at all. The hypothesis that there is a God is the hypothesis of the existence of the simplest kind of person which there could be. A person is a being with power to bring about effects, knowledge of how to do so, and freedom to make choices of which effects to bring about. God is by definition an omnipotent (that is, infinitely powerful), omniscient (that is, all-knowing), and perfectly free person; He is a person of infinite power, knowledge, and freedom; a person to whose power, knowledge, and freedom there are no limits except those of logic. The hypothesis that there exists a being with infinite degrees of the qualities essential to a being of that kind is the postulation of a very simple being. The hypothesis that there is such a God is a much simpler hypothesis than the hypothesis that there is a god who has such and such a limited power. It is simpler in just the same way that the hypothesis that some particle has zero mass or infinite velocity, is simpler than the hypothesis that it has of 0.32147 of some unit of mass or a velocity of 221,000 km/sec. A finite limitation cries out for an explanation of why there is just that particular limit, in a way that limitlessness does not.
That there should exist anything at all, let alone a universe as complex and as orderly as ours, is exceedingly strange. But if there is a God, it is not vastly unlikely that he should create such a universe. A universe such as ours is a thing of beauty, and a theatre in which men and other creatures can grow and work out their destiny. The orderliness of the Universe makes it a beautiful Universe, but, even more importantly, it makes it a Universe which men can learn to control and change. For only if there are simple laws of nature can men predict what will follow from what-and unless they can do that, they can never change anything. Only if men know that by sowing certain seeds, weeding and watering them, they will get corn, can they develop an agriculture. And men can only acquire that knowledge if there are easily graspable regularities of behavior in nature. So God has good reason to make an orderly Universe and, ex hypothesi, being omnipotent, he has the power to do so. So the hypothesis that there is a God makes the existence of the Universe much more to be expected than it would otherwise be, and it is a very simple hypothesis. Hence the arguments from the existence of the Universe and its conformity to simple natural laws are good arguments to an explanation of the phenomena, and provide substantial evidence for the existence of God.
As far as it goes, his account is surely right. But there are two crucial matters beyond its scope. First, the evolutionary mechanism which Darwin describes only works because there are certain laws of biochemistry (animals produce many offspring, these vary in various ways from the parents, and so forth) and certain features of the environment (there is a limited amount of food, drink, space, and so on). But why are there these laws rather than other laws? Perhaps because they follow from the most fundamental laws of physics. But the question then arises as to why the fundamental laws of physics are such as to give rise to laws of evolution. If we can answer this question we should do so. There is again available the same simple answer-that there is a God who makes matter behave in accord with such laws in order to produce a world with animals and men. To develop my earlier point-God has an obvious reason for producing men. He wants there to be creatures who can share in His creative work by making choices which affect the world they live in and the other creatures who live in that world. By the way we treat our environment and our bodies, bring up our children and influence our governments, we can make this world beautiful and its other inhabitants happy and knowledgeable; or we can make it ugly and its other inhabitants miserable and ignorant. A good God will seek other beings with whom to share in his activity of creation, of forming, moulding and changing the world. The fact of a mechanism to produce men is evidence of God behind that mechanism.[3]
Secondly, Darwinian theory is concerned only with the physical characteristics of animals and men. Yet men have thoughts and feelings, beliefs and desires, and they make choices. These are events totally different from publicly observable physical events. Physical objects are, physicists tell us, interacting colorless centers of forces; but they act on our senses, which set up electrical circuits in our brains, and these brain events cause us to have sensations (of pain or color, sound or smell), thoughts, desires and beliefs. Mental events such as these are no doubt largely caused by brain events (and vice-versa), but mental events are distinct from brain events-sensations are quite different from electro-chemical disturbances. They are in fact so different-private, colored or noisy, and felt-from public events such as brain events, that it is very, very unlikely indeed that science will ever explain how brain events give rise to mental events (why this brain event causes a red sensation, and that one a blue sensation). Yet brain events do cause mental events; no doubt there are regular correlations between this type of brain events and that type of mental event, and yet no scientific theory can say why there are the particular correlations there are, or indeed any correlations at all (why did not evolution just throw up unfeeling robots?). Yet these correlations which science cannot explain cry out for explanation of another kind. That is available. God brings it about that brain events of certain kinds give rise to mental events of certain kinds in order that animals and men may learn about the physical world, see it as imbued with color and smell making it beautiful, and learn to control it. Brain events caused by different sights, sounds and smells give rise to different and characteristic sensations and beliefs in order that men may have knowledge of a beautiful physical world and thus have power over it. Darwinism can only explain why some animals are eliminated in the struggle for survival, not why there are animals and men at all with mental lives of sensation and belief; and in so far as it can explain anything, the question inevitably arises why the laws of evolution are as they are. All this theism can explain.
Theism is able to explain the most general phenomena of science and more particular historical facts, but it is also able to explain our own individual religious experiences. To so many men it has seemed at different moments of their lives that they were aware of God and His guidance. It is a basic principle of knowledge, which I have called the principle of credulity, that we ought to believe that things are as they seem to be, until we have evidence that we are mistaken. If it seems to me that I am seeing a table or hearing my friend's voice, I ought to believe this until evidence appears that I have been deceived. If you say the contrary-never trust appearances until it is proved that they are reliable, you will never have any beliefs at all. For what would show that appearances were reliable, except more appearances? And if you can't trust appearances, you can't trust them either. Just as you must trust your five ordinary senses, so it is equally rational to trust your religious sense. An opponent may say, you trust your ordinary senses (e.g., your sense of sight) because it agrees with the senses of other men-what you claim to see they claim to see; but your religious sense does not argue with the senses of other men (they don't always have religious experiences at all, or of the same kind as you do). However, it is important to realize that the rational man applies the principle of credulity before he knows what other men experience. You rightly trust your senses even if there is no other observer to check them. And if there is another observer who reports that he seems to see what you seem to see, you have thereafter to remember that he did so report, and that means relying on your own memory (again, how things seem) without present corroboration. Anyway, religious experiences often do coincide with those of many others in their general awareness of a power beyond ourselves guiding our lives. If some men do not have our experiences, even when our experiences coincide with those of others, that suggests that the former are blind to religious realities- just as a man's inability to see colors does not show that many of us who claim to see them are mistaken, only that he is color blind. It is basic to human knowledge of the world that we believe things are as they seem to be in the absence of positive evidence to the contrary. Someone who seems to have an experience of God should believe that he does, unless evidence can be produced that he is mistaken. And it is another basic principle of knowledge that those who do not have an experience of a certain type ought to believe many others when they say that they do- again, in the absence of evidence of mass delusion.
The case for the existence of God is a cumulative one. I claim that the existence and continued operation of God (normally through the laws of nature, but sometimes setting them aside) can explain the whole pattern of science and history, and also men's most intimate religious experiences.
Mackie has many criticisms of the exposition of my arguments in my book The Existence of God, but most of them are variants of three main counter-arguments. Two of these involve a claim that my theistic hypothesis is not nearly as simple as I suppose. His first argument for this, which occurs in a number of places in his book (especially pp. 100, 129f., 149), is that my category of "personal explanation" (explaining a state of affairs as brought about intentionally by an agent) is not a simple one. For, he writes:
The key power involved in Swinburne's use of 'personal explanation' is that of fulfilling intentions directly, without any physical or causal mediation, without materials or instruments. There is nothing in our background knowledge that makes it comprehensible, let alone likely, that anything should have such a power. All our knowledge of intention-fulfillment is of embodied intentions being fulfilled indirectly by way of bodily changes and movements which are causally related to the intended result, and where the ability thus to fulfill intentions itself has a causal history, either of evolutionary development or of learning or of both. Only by ignoring such key features do we get an analogue of the supposed divine action.[6]Mackie is right to draw our attention to the fact that humans normally execute their purposes indirectly. When I intentionally move my hand, my purposing to move my hand causes the motion of my hand via causing a brain state which in turn causes the hand motion. Although humans directly cause their brain states, they normally do so under a description which describes a brain state in terms of its effects. When I move my hand indirectly, I bring about directly that brain state which causes my hand to move. If that were not so, humans would never through their purposes make any difference to the world; events and actions would never be explicable by the purposes humans were seeking to achieve-which is absurd.
Certainly the purposes of humans are focused not on their brain states, but on the effects of their brain states-that is, they execute their purposes indirectly. But nothing of importance turns on this. Humans could easily learn to bring about brain states described in terms of their intrinsic nature, and seek so to do. When scientists tell me which neuron has to fire in order to cause my hand to move, I can then learn to make that neuron fire directly. Contrary to Mackie, there is plenty "in our background knowledge which makes it comprehensible," indeed "likely that anything should have such a power."
Anyway, contrary to Mackie, the simplicity of a hypothesis is not a matter of the familiarity in the world of experience of its constituents or the relations to each other which the hypothesis claims to hold. We could understand and judge to be highly simple the notion of two (logically) distinct variables being linearly related to each other (that is, x and y having the relation x = ky where k is a constant), even if all actual observable variables were related in more complicated ways. And the model of billiard balls interacting by collision remains a simple model even if it is proved that actual billiard balls never really touch but exert on each other some force at a distance. Whether the relation between purpose and its realization without causal intermediary is simple has nothing to do with whether that relation is instantiated in the world. It is a very simple relation-the occurrence of an event E being brought about by a person purposing to bring about E under a description thereof built into the purpose. The world of mediate experience may prove to be complicated, but it draws our attention to the possibility of simple patterns of causation of kinds exemplified in the world in more complicated ways. Indeed, it is just the complexity of the world which leads us here, as elsewhere in science, to postulate simpler causes at work "behind the scenes." Seeing indirect personal causation at work in the world, we see that personal causation is a type of causation and so personal explanation is a type of explanation. We see that its simplest form would be direct personal causation, and so are led to postulate that at work to explain the complexities around us. The naturalness of the connection between the purpose to bring about E and E allows us to explain Es which are puzzling because they are diverse and complex-for example, the array of puzzling connections between brain states and the mental states which they cause such as sensations; and so, the answer to Mackie's questions
Has God somehow brought it about that material structures do now generate consciousness? But then is this not almost as hard to understand as that material structures should do this of themselves?[7]are "Yes" and "No" respectively.
A different counter-argument of Mackie's to my claim that the theistic hypothesis is very simple is that the "particularity," the detailed features of the phenomena to be explained, has not been removed by postulating an intention in God to bring about those phenomena:
The particularity has not been removed, but only shelved; we should have to postulate particularities in God, to explain his choice of the particular universe he decided to create.[8]The structure of my counter-argument to that was already there in The Existence of God. A perfectly free, omnipotent and omniscient being can only do what is best to do (or do one among many equally best actions). In so far as an agent believes that some action is the best action (that is, what there is most reason to do), he will do it-unless he is subject to irrational inclinations, or desires, which make it hard for him to do what he believes best. God, being perfectly free, is subject to no such inclinations. Further, being omniscient, God will know what is best (that is, what there is most reason to do); He will not have false value-beliefs. Hence, unlike us humans, he will always act for the best. So His freedom is a freedom to choose among the very many equal best actions open to Him. Now we humans are often ignorant and morally insensitive, and in consequence our judgments about which actions are for the best must be tentative. But we can see that it is a good thing that God should make a universe containing men, and (once we have thought about it-as I argued in The Existence of God) we can see that it is good that God should allow men to suffer to a limited extent for a short finite period for the sake of the greater goods which that makes possible -that is, the opportunity for free choice between good and evil, and the opportunity to show patience, courage and compassion. But there are surely certain evils, for example, undeserved suffering of infinite intensity or duration, which God would not be justified in bringing about for the sake of some greater good. Hence the hypothesis of God's existence has the consequence that there will not be such evils. This is not an additional "particularity" which we attribute to God, but follows from His essential nature.
Further, the occurrence of some one rather that any other of a number of equally good states of affairs is made more comprehensible if it is seen as resulting from a personal choice rather than from some random mechanism-for personal choice among equally good alternatives is a mechanism which we see intuitively to be a simple and natural mechanism for selecting alternatives; for it is a mechanism, indeed the only mechanism, of which we have inside experience and whose operation is thus comprehensible.[9] So, for these two reasons (among others), in postulating God we come to a starting point of explanation in which the complex particularity we find around us has a simpler cause from which the complexity flows-and that is always a hallmark of a well-justified explanation. That is why we postulate electrons and protons, neutrons and quarks to explain the miscellaneous data of physics and chemistry.
As well as criticizing my claim about the simplicity of the theistic hypothesis, Mackie claims in various ways that the evidence of observation is not nearly as improbable a priori as I allege- not nearly as unlikely to occur in the normal course of things, that is, if the theistic hypothesis is false, as I allege. In particular, I argued that the totally regular and simple ways of behavior of physical objects; or, as we should say in order to avoid hypostatizing laws of nature, the vast coincidence that there are objects of a very few kinds (electrons, photons, and so forth) all of each kind having identical powers and liabilities, is a very striking coincidence, which is a priori very unlikely. And I went on from there to argue that the hypothesis of a common creator explains the coincidence, since He has the power to bring it about and reason to do so.
Mackie objected:
Inductive extrapolation would not be reasonable if there were a strong presumption that the universe is really completely random, that such order as we seem to find in it is just the sort of local apparent regularity that we should expect to occur occasionally by pure chance, as in a series of random tosses of a coin we will sometimes get a long run of heads, or a simple alternation of heads and tails over a considerable number of throws. Swinburne holds, and his argument requires, that inductive extrapolation is reasonable, prior to and independently of any belief in a god. But, I would argue, this would not be reasonable if there were a strong presumption that the universe is completely random. So he cannot consistently say that, without the theistic hypothesis, it is highly improbable a priori that there are any regularities; for the latter assertion of improbability is equivalent to saying that there is a strong presumption of randomness.[10]Mackie's argument seems to be that in holding that the regularities which we observe are typical of wider regularities in regions of space and time outside the region immediately observed (as I do in rebutting the suggestion that we are observing an untypical segment of space and time) I am already committed to denying the strong presumption of randomness.
Before showing what is wrong with Mackie's argument, it is worthwhile to show it in action in another case. Suppose that there are before us, ready for use, many packs of cards. On examining some of them at random we find that they are all arranged in order of suits and seniority. That allows us to infer that the other packs which we have not examined will also be so arranged. Any normal observer would then immediately suspect that these coincidences are to be explained in terms of something beyond themselves-for example, an agent or a machine constructed by an agent which arranged the packs in order. Mackie, however, if we are to take his argument seriously, would not so react. The mere fact that we can reasonably predict that the unobserved packs will be arranged in order shows that order in packs of cards is a normal thing to be expected, not in need of further explanation.
What has gone wrong? Mackie has misconstrued the argument for design. There is indeed a strong presumption of randomness. But then we observe the regular and simple behavior of all of the many objects which we observe. We argue that if all objects behave in regular and simple ways (h1) our observation will be made; but if only a few objects behave in regular and simple ways (h2) our observation is very unlikely to be made. Although a priori h1 has a much smaller probability than h2, the observations are so much more likely to be observed if h1 than if h2 that the posterior probability of h1 (that is, the probability of h1, given our observations) significantly exceeds that of h2. We then inquire how such an unlikely hypothesis as h1 comes to be true; we seek a higher hypothesis which explains it. Faced with the choice between saying that there are simply brute coincidences in the behavior of objects, and saying that their behavior is brought about by a common cause, a person-we choose the latter on the grounds that its simplicity is high and it gives some probability to what we observe. That after all is how we argue with regard to the packs of cards. Analogy demands that we argue in the same way with respect to the regularities in nature.
It is very unlikely indeed a priori that there should be a Universe made of matter behaving in totally regular ways, giving rise to conscious beings capable of changing themselves and others, making themselves fit for the Heaven of which they have a glimpse in religious experience. Hence the reason which we use about science and history demands that we postulate a simple explanation of these phenomena in terms of a creator and sustainer God. Mackie's reasons for rejecting that view are not adequate.
[2]Oxford: Clarendon Press, 1982.
[3]Recent science has drawn attention to the fact that the initial conditions of the Universe (e.g., the initial velocity of recession of its components) at the time of the "Big Bang," and the physical constants (e.g., the ratio of the electron mass to the neutron mass) occurring in the laws of nature had to lie within very narrow ranges if intelligent life was to evolve. For full-length development of this theme see J.D. Barrow and F.J. Tipler, The Anthropic Cosmological Principle (Oxford: Clarendon Press, 1986); and for a theistic argument developed on the basis of this evidence see John Leslie, "Anthropic Principle, World Ensemble, Design," American Philosophical Quarterly 19 (1982): 141-151.
[4]Existence of God, chapters 9, 10, and 11.
[5]The rest of this section is a shortened version of a paper of mine, "Mackie, Induction, and God," Religious Studies 19 (1983): 385- 391.
[6]Mackie, Miracle of Theism, p. 100.
[7]Ibid., p. 131.
[8]Ibid., p. 100; see also p. 149.
[9]See my The Existence of God, p. 103.
[10]Mackie, Miracle of Theism, p. 148.