Thursday 10/3

Does God Exist?




Our discussion last time of the question,

Why is there something and not nothing?

led us on an intriguing investigation into explaining the existence of the great chain of (dependent) beings such as those we encounter every day and those we are, fundamentally. Despite invoking the Principle of Sufficient Reason twice, our investigation was ultimately inconclusive. The conclusion of the Cosmological Argument is that there must be at least one being whose existence is self-explanatory--although, what that means we ironically never explained--but leaves open whether the being in question is God or the chain of beings itself.

Still, the Cosmological Argument segues neatly into asking, are there perhaps other reasons to think God exists? Today we took up two such arguments. Broadly speaking, arguments for the existence of God either hinge on some feature of the world we notice which we think we must invoke God to explain--these are called 'a posteriori arguments, because they require experience of the world to get traction--or they hinge on some feature of God's supposed nature which necessitates his, her, or its existence regardless of how we find the world--these are called a priori arguments, because they can be established prior to any experience of the world. The Cosmological Argument we considered last time is an a posteriori argument. It requires us to notice the the world consists, it seems, of dependent beings: Beings, recall, the explanation of whose existence presupposes some other being's existence.

The Teleological Argument

Also known as the Argument from Design, the Teleological Argument is likewise an a posteriori argument for the existence of God. 'Teleological' is from the ancient Greek 'telos' (τέλος), or purpose. Recall Aristotle's doctrine of the four causes. Explanations for Aristotle give a thing's material cause, its efficient cause, its formal cause, and its final cause, or the purpose or end for which it was made. Just as an artifact or tool we make (a watch, say, or a compass) has a purpose or end given our interests in creating it, there are purposes or ends to be discovered when we contemplate the complexity of things we find in the natural world. William Paley (1802, "Natural Theology") makes the analogy explicit:

In crossing a heath, suppose I pitched my foot against a stone and were asked how the stone came to be there, I might possibly answer that for anything I knew to the contrary it had lain there forever; nor would it, perhaps, be very easy to show the absurdity of this answer. But suppose I had found a watch upon the ground, and it should be inquired how the watch happened to be in that place. I should hardly think of the answer which I had before given, that for anything I knew the watch might have always been there. Yet why should not this answer serve for the watch as well as for the stone? Why is it not as admissible in the second case as in the first? For this reason, and for no other, namely, that when we come to inspect the watch, we perceive—what we could not discover in the stone—that its several parts are framed and put together for a purpose … [The requisite] mechanism being observed … the inference we think is inevitable, that the watch must have had a maker. ... Every observation which was made in our first chapter concerning the watch may be repeated with strict propriety concerning the eye, concerning animals, concerning plants, concerning, indeed, all the organized parts of the works of nature. … [T]he eye … would be alone sufficient to support the conclusion which we draw from it, as to the necessity of an intelligent Creator. …

So the watch we find is like the eye we find it with: Each evinces a complexity and purposefulness which presupposes an end or purpose for which they were made, and thus a maker with specific intentions.

In his incisive "Dialogues Concerning Natural Religion", David Hume (1798) casts the argument this way:

Look round the world; contemplate the whole and every part of it: You will find it to be nothing but one great machine, subdivided into an infinite number of lesser machines, which again admit of subdivisions to a degree beyond what human senses and faculties can trace and explain. All these various machines, and even their most minute parts, are adjusted to each other with an accuracy which ravishes into admiration all men who have ever contemplated them. The curious adapting of means to ends, throughout all nature, resembles exactly, though it much exceeds, the productions of human contrivance; of human design, thought, wisdom, and intelligence. Since, therefore, the effects resemble each other, we are led to infer, by all the rules of analogy, that the causes also resemble; and that the Author of Nature is somewhat similar to the mind of man, though possessed of much larger faculties, proportioned to the grandeur of the work which he has executed. By this argument a posteriori, and by this argument alone, do we prove at once the existence of a Deity, and his similarity to human mind and intelligence.

We can spell out the argument in one of several ways. Here is one approach:

The Teleological Argument
  1 The world itself and the natural things discovered in it have teleological complexity.  
  2 If the world itself and the natural things discovered in it have teleological complexity, then the world itself and each of the natural things discovered in it must have been made for a purpose or end.  
  3 If the world itself and each of the natural things discovered in it must have been made for a purpose or end, then there must be a maker or creator of the world itself and each of the natural things discovered in it.  
4 There must be a maker or creator of the world itself and each of the natural things discovered in it. 1, 2&3

So stated, the argument is valid, but is it sound? Are all the premises true? Set aside premises (1) and (3) to focus on premise (2), which bluntly claims that teleological complexity we find in nature in the same way that we find teleological complexity in, say, a watch implies that there is a designer or creator. So, the idea goes, when we fully grasp the astounding capability of the human eye, we cannot help but attribute to it teleological complexity, and that complexity (pace the watch) its having been made for some purpose or end. But is this true? The point of Evolutionary Theory is to provide the explanatory resources to provide a fully mechanistic explanation for the existence of the eye in all its complexity, as resulting from wholly natural processes (over unimaginably long stretches of time and with enormous dollops of energy pouring in from the Sun!) If Evolutionary Theory has any credence, we confront the possibility that the complexity we encounter may appear to be the result of intentional or purposeful or deliberate processes, but mechanistic processes like natural selection suffice to explain the complexity. In light of the explanations provided by Evolutionary Theory, we have good reason to reject premise (2). Likely this is why evolutionary theory has long been taken to be a serious threat to religious belief, even if (for reasons we did not discuss) it need not be taken to pose such a threat.

Once again, however, remember that a valid argument can have a false premise and still have a true conclusion. Showing a premise of valid argument false gives one no reason whatsoever to think the conclusion is false. Validity doesn't work that way. At most we can say that the Teleological Argument, promising though it appeared to be, provides us no reason to think God exists. But having no reason to think God exists is not immediately a reason to think God does not exist. We want to look further for additional arguments.

The Ontological Argument

This in fact is the only a priori argument for the existence of God we will consider this semester. It is neither trivial nor straightforward. St. Anselm (11th century) develops his version of the Ontological Argument by arguing that it is impossible to understand the nature of God while denying the existence of God on pain of contradiction. Let us unpack this as follows:

The Ontological Argument
  1 God is that being than which none greater can be conceived.  
  2 Suppose it is not the case that God exists.  
  3 If it is not the case that God exists, then God is a being than which a greater being can be conceived, one that exists.  
  4 If God is a being than which a greater being can be conceived, one that exists, then it is not the case that God is that being than which none greater can be conceived.  
5 It is not the case that God is that being than which none greater can be conceived. 2, 3&4
6 God is that being than which none greater can be conceived and it is not the case that God is that being than which none greater can be conceived. 1&5
7 God Exists 2&6

That may seem too fast. The logical form of the argument is famous. Indeed, it is a form used in mathematics, logic, and philosophy all the time. It's called a Reductio ad Absurdum, or Reductio for short. The idea is that we start with the premise that denies God's existence and argument from that denial and God's nature to a logical contradiction--a proposition of the form, P ∧ ∼P. In this particular argument the contradiction is validly deduced at sub-conclusion (6). Notice that we have a valid argument from our premises to a contradiction. But as a quick truth table will demonstrate, a contradiction is a logical falsehood. It is necessarily false. Recall that valid argument with a false conclusion must have at least one false premise. So we infer that the denial of the premise leading the contradiction must be true--here, that God exists.

The trouble with the argument is, of course, logical. We have actually 4 premises in the argument. Why conclude at (7) by denying (2)? We could just as well deny (1), or, granting (1), deny (3), or, granting (3), deny (4). Anselm thinks (1), (3), and (4) are just obviously true, and he may be correct when it comes to (4). But what about (3)?

The monk Guanilo, about whom we know nothing apart from this very criticism, called into question (3) by inviting us to consider an island than which none greater can be conceived. By (3), if the island than which none greater can be conceived does not exist, then a greater island can be conceived, one which exists. Thus the proposition expressed by (3) generalizes to permit showing anything whatsoever exists: The greatest Island, the greatest Unicorn, the greatest car, or what have you.

In defending (3), Anselm might have a response. Things like islands, cars, and unicorns have relative properties. One car may be faster than another, or better at cornering. One island might have better sand beaches than another, or better sunsets. God's properties are not relative, it seems, but absolute. Thus God is said to be omnipotent, or all-powerful, omniscient, or all-knowing, or omnibenevolent, or all-loving. Yet these very properties may in turn be problematic, for consider:

The Problem of Evil
  1 If God exists, then God is omnipotent (all-powerful), omniscient (all-knowing), and omnibenevolent (perfectly good).  
  2 If God is omnipotent, omniscient, and omnibenevolent, then it is not the case that evil exists.  
  3 Evil exists.  
4 Either God is not all-powerful, God is not all-knowing, or God is not perfectly good. 2&3
5 God does not exist. 1&4

As we discussed, there are a number of responses possible, and religions have embraced one or other of these responses. We might reject (1) by holding the God exists, but is not all-powerful, not all-knowing, or maybe not all-loving (perfectly good). Or we might reject (2), although it is hard to see just how, frankly. Or we might reject (3), arguing that what we perceive as evil is not truly evil.

At the end of the day today, we found that our investigation into God's existence was inconclusive. None of the arguments for God's existence escape cogent criticism, nor does the one argument we considered explicitly against God's existence. Our puzzle remains, resisting our best efforts. Is it, then, not a puzzle, but a paradox, unresolvable in principle? God must exist, yet God cannot exist? Or have we missed something important?

By the way, permit me to add that I am thoroughly enjoying this class. I'm only sorry that the schedule I set is not allowing for the kinds of in-depth discussions on which so many of you seem keen to contribute. I may, then, adjust our schedule a bit, maybe by taking out some material, so as to allow more time on each puzzle. Stay tuned.