In Arguing for Atheism Le Poidevin makes a central argument that theism is a bad explanation. He makes several arguments to back this claim. That theism takes the notions of cause and chance out of their original contexts (I have already discussed these points a bit in so I will not discuss them here), that God is not a good casual explanation, that personal explanations incorporating God are suspect, and that theism not have much explanatory virtue. I will deal with these 3 points backwards!
Poidevin highlights 2 explanatory virtues that theistic explanations having to do with a first cause do not have; they are not informative, and they have no “connections to generalizations” (pg 36). I don’t think it is controversial to say that positing a “first cause” is not at all informative; that is does not explain it is the case that x occurred or did not. Le Poidevin helps with this illustration: someone’s house was smoking and you walk over to a crowd which has gathered to watch the spectacular event. You ask a bystander for an explanation and he told you that a smoke-producing event had occurred. Le Poidevin thinks that introducing a first cause is as useful as the smoke-producing event explanation and I am inclined to agree—this however changes once you introduce and agent and try weave a personal explanation. A first cause also appears to have no connection to generalizations. To generalize is to say that “A-type events tend to cause, in certain situations, B-type events” (pg 42). An example of this would be chemicals combining in a certain context to produce another chemical. It is also clear that in order to generalize you need to have background knowledge; this background knowledge will include natural laws of causation and whatnot. However when we try to explain the existence of the universe we try to explain the existence of the laws and whatnot without the actual laws themselves; this means that no generalizations can be made. I believe Poidevin’s points are quite sound but they are not just problems for theistic explanations of the universe. They seem to describe a short of humble posture towards the explaining the universe; it appears as though we cannot casually explain it.
It however is quite apparent that not all explanations are causal explanations; another type of explanation (which is introduced by Swinburne in his book The Existence of God which I have yet to read) is a personal explanation. This involves an agent’s action and those agent’s intentions which led to that action. For example if a person does something they intend to achieve an end. If I have an intention to by nice to people I will try accomplish through a variety of means (in that way personal are quite teleological; “explanations in terms of purpose”). This is probably a gratuitously over complicated explanation of what a personal explanation, but Oh well I am quite exhaustedly incapacitated. It certainly seems like intentions are not causes in the normal way we describe causes but I believe I have already discussed this elsewhere. Any way, one way in which Le Poidevin points out those personal explanations are not the best at explaining the universe are is because they are contingent. Intentions are contingent because it seems like they could obtain or could not obtain. In this way if we are trying to explain the existence of the universe and point to intentions it seems like intentions either could be or could not be in the same way the universe could be or not be and if it is the case that the universe needs an explanation because it is contingent then intentions will need an explanation as well since they are contingent.
Finally Le Poidevin makes the argument that necessary facts cannot explain contingent ones. I have already made comments on thisHere as well as the intention objection that I discussed above.
Le Poidevin, Robin. Arguing for Atheism: An Introduction to the Philosophy of Religion. London: Routledge, 1996. N. pag. Print.