First published Tue Mar 9, 2004; substantive revision Mon Aug 8, 2011

The main purpose of this article is to explore the differences between atheism and agnosticism, and the relations between them. The task is made more difficult because each of these words are what Wittgenstein called family resemblance words. That is, we cannot expect to find a set of necessary and sufficient conditions for their use. Their use is appropriate if a fair number of the conditions are satisfied. Moreover even particular members of the families are often imprecise, and sometimes almost completely obscure. Sometimes a person who is really an atheist may describe herself, even passionately, as an agnostic because of unreasonable generalised philosophical scepticism which would preclude us from saying that we know anything whatever except perhaps the truths of mathematics and formal logic.

Atheism means the negation of theism, the denial of the existence of God. I shall here assume that the God in question is that of a sophisticated monotheism. The tribal gods of the early inhabitants of Palestine are of little or no philosophical interest. They were essentially finite beings, and the god of one tribe or collection of tribes was regarded as good in that it enabled victory in war against tribes with less powerful gods. Similarly the Greek and Roman gods were more like mythical heroes and heroines than like the omnipotent, omniscient and good God postulated in mediaeval and modern philosophy. As the Romans used the word, atheist could be used to refer to theists of another religion, notably the Christians, and so merely to signify disbelief in their own mythical heroes.

The word theism exhibits family resemblance in another direction. For example should a pantheist call herself an atheist? Or again should belief in Plato's Form of the Good or in John Leslie's idea of God as an abstract principle that brings value into existence count as theism (Leslie 1979)? Let us consider pantheism.

At its simplest, pantheism can be ontologically indistinguishable from atheism. Such a pantheism would be belief in nothing beyond the physical universe, but associated with emotions of wonder and awe similar to those that we find in religious belief. I shall not consider this as theism. Probably the theologian Paul Tillich was a pantheist in little more than this minimal sense and his characterising God as the ground of being has no clear meaning. The unanswerable question Why is there anything at all? may give us mystical or at any rate dizzy feelings but such feelings do not differentiate the pantheist from the atheist. However there are stronger forms of pantheism which do differentiate the pantheist from the atheist (Levine, 1994). For example the pantheist may think that the universe as a whole has strongly emergent and also mind-like qualities. Not emergent merely in the weak sense that a radio receiver's ability to receive signals from distant stations might be said to be emergent because it is not a mere jumble of components (Smart 1981). The components have to be wired together in a certain way, and indeed the workings of the individual components can be explained by the laws of physics. Contrast this with a concept of emergence that I shall call strong emergence. C. D. Broad in his Scientific Thought (Broad 1923) held that the chemical properties of common salt could not even in principle be deduced from those of sodium and chlorine separately, at the very time at which the quantum theory of the chemical bond was beginning to be developed. Though the mind has seemed to some to be strongly emergent from its physical basis, it can be argued that developments in the philosophy of mind, cognitive science and neuroscience favour weak emergence only.

One strong form of pantheism ascribes mental properties to the cosmos. If the weak sense of emergence was adopted we would be faced with the question of whether the universe looks like a giant brain. Patently it does not. Samuel Alexander asserted, rather than argued, that mentality strongly emerged from space-time, and then that at some future time there will emerge a new and at present hardly imaginable level which he called deity (Alexander 1927). It is hard to tell whether such an implausible metaphysics should be classified as as pantheism or as theism. Certainly such a deity would not be the infinite creator God of orthodox theism. A. N. Whitehead, too, had a theory of an emergent deity, though with affinities to Platonism, which he saw as the realm of potentiality and therefore he connected the atemporal with the contingent temporal deity (Whitehead 1929). Such views will not deliver, however implausibly, more than a finite deity, not the God of core theism. God would be just one more thing in the universe, however awesome and admirable.

The weak form of pantheism accepts that the physical universe is all and eschews strong emergence. Sometimes the weak form of pantheism is rhetorically disguised as theism, with God characterised as absolute depth or some equally baffling expression, as by Paul Tillich. At any rate, whether or not we accept pantheism as a sort of theism, what we mean by atheism will vary according to what in the dialectical situation we count as theism.

This brings us naturally to the question of what we might consider to be an adequate concept of God, whether or not we wish to argue for the existence of such a being. Some profound remarks were made on this by J. N. Findlay in his article (Can God's Existence be Disproved? (Findlay 1949). The heathen may worship stocks and stones but does not see them as merely stocks and stones. More and more adequate conceptions of God still portray God as limited in various respects. A fully adequate conception of God, Findlay said, would see God as not only unlimited in various admirable properties but also as a necessarily existing being. Thus There is one and only one God would have to be a logically necessary truth. Now logic, he held, is tautologous and without ontological commitment. So God's necessary existence would have to be something different from logical necessity. The trouble is how to see what this could be.

It might be replied that there are non-trivial necessary existential propositions in mathematics, such as There are infinitely many primes which implies of course the number 7 exists. (We can ignore the unhelpful Something exists which is allowed by standard first order logic purely for convenience as few would need to apply logic to discourse about an empty universe for which in any case there are separate rules for determining validity or otherwise.) It is well known that Frege in his Foundations of Arithmetic claimed to reduce arithmetic to logic. However in effect he was using a free logic without ontological commitment. Claims to reduce set theory (and so analysis) to logic are of course even more problematic. Would it help towards an adequate conception of God if we said that God has the sort of existence or non-existence that prime numbers have? One might say not much. In any case it is dangerous to talk of types of existence because it treats existence as though it was a property. At the time that he wrote his article Findlay was following the logical positivist line that logic and mathematics are alike tautologous. In the case of mathematics this can be seriously questioned. Also most theists would say that prime numbers are too abstract to be compared to God, though perhaps not John Leslie who has argued that God is a principle that brings value into existence (Leslie 1979 and 1989). We are still left with Findlay's challenge as to what a conception of God as a necessary being could be.

One thing that will not differentiate the theist from the atheist is to say that God, if he exists, is necessary in the sense of not being dependent on anything else for his existence. The atheist will say that the universe fits this bill because the universe contains everything that there is and so is not caused by anything else. It is indeed hard to see what an adequate conception of God and his necessary existence could be. For the purposes of this article, let us explore what the relations and lack of relations between atheism and agnosticism could be. Here we shall neglect the requirement of necessary existence and in a later section we shall consider the case of a posteriori arguments for the existence of a mind-like creator of the universe. Of course without the requirement of necessity it raises the intelligent child's question Who made God? Still, this might be regarded as inevitable but excusable in an a posteriori argument in which the hypothesis of a purposive creator is put forward and claimed to be justified much in the manner of any scientific hypothesis.

Continued here:
Atheism and Agnosticism (Stanford Encyclopedia of Philosophy)