The philosophy of religion is an examination of the meaning and justification of religious claims. Claims about how the world is, often embodied in creeds, are more typical of Western religions—Christianity, Judaism, and Islam—than of Eastern religions such as Buddhism, Hinduism, and Confucianism. These latter tend to concentrate much more on the practice of a way of life than on a theoretical system by means of which (among other things) to justify that practice. Hence Western religions have proved a more natural target for the philosophy of religion. The central claim of Western religions is the existence of God; and the two major problems here are: Can a coherent account be given of what it means to say that there is a God; and, if it can, are there good reasons to show that there is or that there is not such a God?

In order to explain what it means to say that there is a God and to make other religious claims, theists use ordinary words such as ‘personal’, ‘creator’, ‘free’, ‘good’, etc., which we first learn to use from seeing them applied to mundane objects and states; or technical terms such as ‘omnipotent’, defined ultimately in terms of ordinary words. The question then arises: Do these ordinary words have different senses when used for talking about God from the senses they have when used for talking about mundane things, or the same senses? To use the technical terms: Are they used equivocally or univocally with their mundane senses? If the former, how could we understand what the new, religious senses are? If the latter, how could God be the inexpressible mysterious other which he is supposed to be, when he can be described by the same words having the same senses as can mundane things? The answer given by Aquinas was that religion often uses words in somewhat the same and somewhat different senses from their mundane senses, i.e. in analogical senses. We learn the meanings of the relevant words from their application to mundane things—e.g. learn the meaning of ‘wise’ from seeing it applied to wise men, such as Socrates—and then, when they are applied to God, suppose them to be attributing to him the nearest thing to the mundane property which could belong to the cause of all things. This answer presupposes that at least some words—e.g. ‘cause’—are used univocally in religious and mundane discourse; and it has the consequence that the other words are not used in senses very different from their mundane senses.

God is said to be ‘personal’, ‘bodiless’, ‘omnipresent’, ‘creator and sustainer of any universe there may be’, ‘perfectly free’, ‘omnipotent’, ‘omniscient’, ‘perfectly good’, and ‘a source of moral obligation’, and to have these properties ‘eternally’ and ‘necessarily’. It has been a major concern of the philosophy of religion to investigate whether a coherent account can be given of the meaning of these expressions (bearing in mind the possibility that some of them have senses analogical with their normal senses), and whether they can be combined in a logically consistent way, so that the claim that there is a God can be expressed in an intelligible and coherent way. For example, is God's being eternal to be understood as his being everlasting (existing at each moment of unending time), or as his being timeless (outside time). (Eternity.) There are serious difficulties in making sense of the idea of a personal being existing timelessly—that is, at no moment of time. How could he cause events, except by acting as or before they happen; or know about events, except by those events causing his knowledge as or after they occur? Yet if we think of him as everlasting, does his omniscience mean that he knows what we will do before we do it; and in that case how can our actions be free? Does God's being a source of moral obligation mean that he could command us to torture children, and that it would become our duty to do so if he commanded it?

Given that a coherent account can be offered of what it is for there to be a God in more or less the traditional sense, we come to the question of whether there is any good reason to believe that such a God exists. Some have claimed that if one finds oneself believing that there is a God, then it is rational to believe this without looking for arguments in support of the claim—just as it is rational for me to believe that I ate toast for breakfast or am now listening to a car passing the window, if I find myself believing these things. I do not need further evidence in order rationally to believe such a thing—unless, that is, I acquire evidence to suppose that the belief is false, and in that case I may need evidence confirming the belief in order to outweigh the former evidence and so to continue rationally to hold the belief. The view that the belief that there is a God needs no prior support from other evidence in order to be held rationally is the view of ‘reformed epistemology’, advocated by Alvin Plantinga and developed in a 1984 collection on Faith and Rationality which he co-edited. Basic beliefs are ones which the subject believes, but not for the reason that they are supported by any other beliefs which he holds. Beliefs are ‘properly basic if the subject is justified in holding them even if not supported by other beliefs’. What Plantinga calls ‘classical foundationalism’ is the view that the only properly basic beliefs are self-evident beliefs (beliefs in obvious logical truths, such as that 2 + 2 = 4), incorrigible beliefs (beliefs about our current mental states), and beliefs evident to the senses (beliefs about what we are now perceiving via the five senses). It would seem to follow from classical foundationalism that belief that there is a God cannot be properly basic, and so requires to be based on other beliefs, i.e. to be justified by argument from other beliefs. Plantinga argues (for reasons quite apart from those concerned with religious beliefs) that classical foundationalism has too narrow a class of properly basic beliefs (it should, for example, include memory beliefs). And further, he argues, it is self-defeating, because belief in classical foundationalism itself is neither (by its own standards) a properly basic belief nor, apparently, supportable by properly basic beliefs. Yet once we abandon classical foundationalism, he claims, we have no good reason for denying that belief that there is a God may be properly basic.

There is much to be said for the principle that it is rational to hold any belief with which one finds oneself, in the absence of counter-evidence—a principle sometimes called ‘the principle of credulity’. But Plantinga is not advocating this as a general principle; rather, he holds that ‘there is a God’ may be held without further justification, even if ‘I am now aware of the Great Pumpkin’ may not; and he has recently developed a theory of epistemology which has this consequence. (See his Warranted Christian Belief.) This theory concerns what makes a belief ‘warranted’. Warrant is the characteristic which turns true belief into knowledge. If my belief that the Second World War ended in 1945 is warranted, then if it is also true, I know that the Second World War ended in 1945. (A belief being ‘warranted’ is very similar to its being justified or rational—that is, the believer being justified or rational in holding the belief.) Plantinga's account of warrant is a complicated one, but its central component is that to be warranted a belief must be produced in the right way—that is, by a ‘properly functioning process’. Thus perception, memory, and induction are all processes which lead us to acquire beliefs; and plausibly we are functioning properly when we acquire beliefs by means of them (in the absence of counter-evidence). So, any belief of mine acquired by perception will be warranted (in the absence of counter-evidence—for example, my memory that I have just ingested a hallucinatory drug). So too will any belief acquired by induction from my perceptual beliefs. Plantinga suggests that we all have a sense additional to the normal five, a ‘sense of divinity’ which produces in many of us the belief that there is a God; and that, since there is a God (Plantinga claims), our cognitive faculties are functioning properly when the ‘sense of divinity’ does produce that belief. If he is right about this, then (unless—improbably—the belief is acquired by some other process) whenever we find ourselves with the belief that there is a God, we are warranted in continuing to hold it (so long as we do not find evidence or arguments tending to show that there is no God). But if we do not find ourselves with the belief that there is a God to start with, or our belief is only a weak one outweighed by counter-evidence (for example, the evidence of suffering suggesting that there cannot be a perfectly good being in charge of the universe), Plantinga does not give any positive reason to hold that belief or hold it in a stronger form so that it is not outweighed. He is concerned only to show that a simple religious believer who can give no arguments for his belief may still be warranted in holding it.

If atheists and weak believers are to be given a strong belief that there is a God, they need to be shown that other things which are more evident to them make it probable that there is a God by public standards of what is evidence for what. There has been a long history in Western philosophy of positive arguments for the existence of God. Anselm, Aquinas, Duns Scotus, Descartes, and Leibniz and innumerable other philosophers have given such arguments. Most of these arguments are arguments from observable phenomena to a God who, it is claimed, provides the explanation of their occurrence. (One exception is the ontological argument, which has as its premisses pure conceptual truths.) The cosmological argument argues from the universe to a God who creates it; the teleological argument argues from the orderliness of the universe (either in respect of conforming to laws of nature, or in containing animals and humans in an appropriate environment) to a God who makes it thus. The argument from consciousness argues from the existence of conscious embodied agents (humans and animals) to a God who endows them with consciousness. The argument from religious experience argues from the occurrence of religious experiences, in the sense of experiences in which it seems to the subject that he is aware of God, to millions of people of different centuries and cultures, to a God of whom they really are aware.

It is crucial for assessing the worth of such arguments whether they are to be regarded as deductive or inductive (or probabilistic) arguments, and whether they are to be taken separately or together. A deductively valid argument is one in which if you assert the premiss or premisses from which it starts, but deny the conclusion, you contradict yourself. So, for example, the cosmological argument will be a valid deductive argument if and only if ‘there is a universe, but no God’ involves a contradiction—if it is like ‘he is less than 5 feet tall and more than 6 feet tall at the same time’. It does not at first sight look as if ‘there is a universe, but no God’ is self-contradictory. If, however, the arguments are taken as inductive arguments, then they will be like the scientist's arguments from observable data to his hypothesis of unobservable entities which cause the observable data—like the physicist's observations of lines on photographic plates to his conclusion that they are caused by electrons or positrons; the arguments do not guarantee the truth of the scientist's hypothesis, but they can make it very probable. Arguments for the existence of God have to be weighed against arguments against the existence of God. The most important of these is provided by the problem of evil: that an omnipotent and perfectly good God would not allow the occurrence of pain and suffering.

The arguments for the existence of God are more plausible if regarded as inductive, and taken together. Arguments from observable data to an explanatory hypothesis in science, history, or any other area, in the opinion of this writer, make the hypothesis probable in so far as

(1) the hypothesis makes probable the occurrence of the data, (2) the occurrence of the data is not otherwise probable, and (3) the hypothesis is simple. (Simplicity.)

(1) such as you would expect to find if Jones committed the crime, and (2) not otherwise to be expected, and (3) the hypothesis is simple.

(1) this order is a good state, which in consequence a God would probably bring about, but which (2) otherwise would be a vast improbable coincidence, and (3) that a God is a simple being.

The main argument against the existence of God has always been the ‘argument from evil’—that is, from pain and malevolence. Theists sometimes claim that since by hypothesis God is so much greater than us, we cannot expect to understand why he allows all the things that happen to happen; there are bound to be puzzling phenomena such that we cannot understand why God allows them to occur, and so we should not count evil as evidence against the existence of God. However, almost all atheists and many theists have felt that the claim that God is perfectly good would be empty of meaning unless some explanation could be given of why, being perfectly good, he allows the enormous amount of pain and malevolence that there is in the world. An explanation of this is called a ‘theodicy’. Evils are traditionally divided into moral evils (ones knowingly caused or allowed to occur by humans) and natural evils (the ones for which humans are not responsible, such as the effects of disease and earthquake). A central plank of most theodicies is the ‘free will defence’ to moral evil: the claim that if God is to give humans the great good of a free choice between good and evil, it is inevitable that there will be some moral evil. (There would be, it is claimed, a contradiction in supposing that God could cause us freely to choose the good—for to choose ‘freely’ is to choose without being caused how to choose.) Theodicy needs more complicated arguments to attempt to deal with the problem of natural evil. (Evil, the problem of.)

All religions have set a high value on faith. But how is ‘faith’ to be understood? (Faith and reason.) If it is understood as forcing yourself to believe what seems probably false, there would seem to be little merit in it. But if it is seen as giving oneself totally to attain a great good (e.g. the vision of God for oneself and others), when it is no more than probable that this goal is attainable, it would seem more plausibly a virtue.

Other claims, common to all Western religions, include the claims that God hears prayers and answers them, sometimes by miracles; that God has revealed certain truths; and that there is a life after death in which the good will enjoy the vision of God and the bad will be deprived of it for ever. A miracle has often been understood as a violation of a law of nature, by God intervening in the world. But then, how can something be a law of nature if it can be violated, and so there can be exceptions to its operation; is not a purported law of nature which does not always predict accurately not really a law of nature? One answer to this is to regard exceptions to the operation of a purported law of nature as showing it to be no true law of nature only if they are repeatable exceptions; you only show ‘all metals expand when heated’ not to be a law of nature if you show that regularly when a certain metal is heated under certain conditions, it expands. The occasional non-repeatable exception is a violation; and, if brought about by God, a miracle. Hume (Enquiry Concerning Human Understanding, sect. 10) has a famous argument purporting to show that there could never be a balance of evidence in favour of the occurrence of a miracle thus understood. To show a miraculous event E to have occurred at time t, we need to show first that there is some law of nature which its occurrence would violate. We need a lot of evidence from what has happened on many other occasions to show some purported law L to be a law of nature (e.g. evidence of observers to show that on many other occasions, objects have behaved in the way predicted by L). But then that evidence will tend to show that L will be obeyed at other times also, including at t. The evidence in favour of the occurrence of E will consist only of the testimony of a small number of observers; and so the force of their evidence will always be outweighed by the force of the testimony of many observers who testify to the operation of L on many other occasions. An obvious response is that the sums are not quite so simple—evidence of observers as to what happened on other occasions is only indirect evidence about what happened at t, whereas the evidence of the observers at t is direct evidence, and so has much more force.

Why does God not make nature perfect to begin with? Why does he need to intervene in the natural order? One reason that he might have is—in order to answer prayer. He wishes to bring about good in response to human request; and, to make that possible, he leaves nature capable of improvement. Another reason for performing a miracle would be to give his authority to some prophet who had publicly prayed for the miracle to occur or whose teaching was forwarded by the miracle, and so thereby publicly to authenticate the prophet's teaching as a revelation from God. Philosophy of religion has a concern with whether God would be expected to provide a revelation, and what are the tests that he has done so (e.g. whether the Koran, or the Christian Bible and Creeds record such a revelation). Joseph Butler's The Analogy of Religion is a famous discussion of these issues.

Whether it is coherent to suppose that human beings can survive their death depends on the correct account of personal identity (see also immortality). If there can be such life, the issue arises whether what Christianity, Islam, and some other religions have claimed as the character of the afterlife is compatible with the goodness of God. Such religions claim that the good (judged so to be in virtue of their faith or works—Protestants have emphasized one, Catholics the other) will enjoy the vision of God for ever, whereas the bad will be permanently deprived of it, possibly in a Hell of endless sensory pain. Could a good God act thus? One answer is that in their life on Earth human beings freely form their character; and only a person with a good character would want to have, and so be capable of enjoying, a vision of God—it is humans who make the ultimate choice of their fate.

In recent years the philosophical techniques and results of the Anglo-American tradition of philosophy have been applied not merely to the most general claims of Western religions, but also to specifically Christian doctrines (as well as occasionally to the specific doctrines of other religions). The Christian doctrines include the three central Christian doctrines of the Trinity (that God is three persons of one substance), the Incarnation (that God became incarnate as a human being, Jesus Christ), and the Atonement (that Christ's life and death atoned for the sins of humans). The initial philosophical task is to see how far a clear meaning can be given to these doctrines; and the next task is to consider if there are any grounds for believing them true. It is normally supposed that revelation will provide the main grounds, but there may also be a priori arguments for or against their truth. This interest in specifically Christian doctrines has gone along with investigation of how far it is possible to compare religions in respect of their truth-claims and their ability to provide ‘salvation’, and to whether one can say with justification that one religion is ‘the true religion’ or at least better than other religions.

R. M. Adams, The Virtue of Faith (Oxford, 1987).Find this resource:

W. L. Craig (ed.), Philosophy of Religion (Edinburgh, 2002).Find this resource:

P. Helm (ed.), Faith and Reason (Oxford, 1999).Find this resource:

J. L. Mackie, The Miracle of Theism (Oxford, 1982).Find this resource:

M. Peterson et al. (eds.), Reason and Religious Belief, 2nd edn. (Oxford, 1997).Find this resource:

A. Plantinga, Warranted Christian Belief (Oxford, 2000).Find this resource:

R. Swinburne, Is There a God? (Oxford, 1996).Find this resource: