I am currently involved (on and off) in an informal dialogue on religion, and so forth, with a dear friend of mine. He is not Catholic, but he is intellectually honest (a rare quality, no matter what your religious persuasion). During the course of this discussion, he basically asked (I paraphrase, of course, do tell me if I'm wrong, Charlie): if you can itemize all the physical causes for every observable phenomenon, why would you need to bring in the notion of God at all? Isn't this just multiplying causes unnecessarily? Why would a rational being ever need to consider the existence of God based on an examination of nature?

I think that the assumption that you can, at least in theory, quantify every cause of any given phenomenon is itself dubious, but whatever. Let's say that there is no obstacle. Given that assumption (and world enough and time), if you consider the banana slug, you could eventually discover every factor which governed the being of the banana slug entity. Its physical construction, down to atomic level, would be transparent to you; its genetic code you could master and independently reproduce. This same genetic code would contain within it evidence of the countless aeons of increasing complexity which allowed the universe to go from 'zero' to 'slug,' thus eliminating the need for an intelligent designer in the historical sense. The continued subsistence of the banana slug you could attribute to a complex, but not supernatural, set of contingencies (a certain temperature, atmospheric makeup, humidity, altitude, means of nutrition, complementary organisms, and so forth).

Very well. Now why, considering the banana slug, would you ever think of God? Haven't you given a thorough account of its whys and wherefores? Isn't the origin of the banana slug a question quite independent of the plausibility of God's existence?

My answer is hard to articulate. I think that, even after you had comprehended the proximate causes of the banana slug, no matter how extensively, you would still be filled with wonder about the animal. The banana slug itself transcends the chain of causes that led to its existence. It is more than a quantifiable conglomeration of atoms; it is an organism, ordered and beautiful. There is a joy that we feel on apprehending beautiful creations (natural or artificial), and a desire for knowledge regarding them, that cannot be fully satisfied by an itemization of their history and components. If we experience a marvelous work of art, we are not content with knowing the physical makeup of the work of art (material cause), who created the art (agent cause), or what the structure of the work of art is (formal cause). We also want to know what it means (final cause). The same thing applies to natural objects; we want to know why the banana slug is there, in a fuller sense than is possible through knowing what its parents were and what it eats to stay alive. Now. Perhaps this sense of longing for a deeper comprehension of the natural world is a relic of a more primitive intellectual tradition; an inaccurate anachronism, which we should quash in our souls. Or perhaps, as I believe, the natural world does have a final cause, and our innate desire to know the ultimate causes of things may well bring us to consider the existence of God.

Nota bene: I haven't tried to provide a proof of God's existence; just a reason why you might consider it, given the universe at hand. And this is in no way a condemnation of scientific inquiry...far from it. However, the question remains of why a banana slug is good and beautiful...and natural science would not have come about if the natural world was not good and beautiful...but still, it cannot answer that question.

Nota bene (2): If this is all just babble (and it may well be), just ignore it. I don't know anything anyway, and the more philosophy I read, the less I know. I've probably accumulated negative knowledge, at this point.