The Argument from Design

The "Design Argument“ (like the Cosmological Arguments and unlike the Ontological Argument) draws on observations about the world. Further, the "Design Argument“ is similar to Leibniz’s version of the Cosmological argument in that both arguments attempt to establish that a supernatural being (God) is the only way to explain what we observe.

But remember, the Cosmological Argument begins with the very general fact that the universe exists, and then attempts to extablish that God exists. The Argument from Design does not begin with this general fact. Instead, it draws on specific features about the world (namely, various examples of  "complex harmony" we find in the universe).

"Complex Harmony"

In class, I used the phrase "complex harmony" to describe a range of different examples. This phrase was meant to capture the two points that are common to the examples cited by proponents of the Design Argument ("complexity" and "harmony"). I briefly discussed a few possible examples of "complex harmony" that a proponent of the Design Argument might point to: The point of these examples is that they seem to cry out for an explanation. The proponent of the Design Argument claims that the best explanation for these example involves God. 

The Official Argument

As I described in class, I think it's best to view the Design Argument as, officially, an "inference to the best explanation". It relies on a general principle that is is reasonable to believe the best explanation of a range of observations (premise 1, below). I reconstructed the "official argument" as follows: The conclusion of the "official" argument is that the universe was designed. The idea of course, is that the universe was designed by a supernatural designer, i.e. God. 

The Watch Analogy

As it stands the official argument may be less than convincing. Specifically, we might wonder why we should buy premise 3,  Why should we think that the best explanation of these examples is that the universe had a designer?

To motivate the Design Argument, proponents often discuss an analogous arguments. (In your reading for class, Blackburn cites Hume to describe the Design Argument. Hume will go on to question the argument, but when he first discusses it, he puts it in terms of an analogy.) The point of such analogies is to help motivate the claim that the best explanation of something's "complex harmony" is that the thing had a designer. (That is, the analogies are supposed to support premise 3 above.)

In an especially famous statement of the Design Argument, William Paley draws an analogy involving the discovery of a watch in a forest. The set-up is as follows: Let's say you were walking through the woods and you came across a watch sitting on a stump. Upon inspection of the watch, you would find that it exhibits a great deal of "complex harmony". Not only would you find that it is a complex bit of machinery, you would see that the gears seem to be working together. The complexity seems to be serving some function.

Paley claims that the reasonable thing to infer is that the watch had a designer. Thus:

Assessing the Argument

I went into the Design Argument in slightly greater detail than Blackburn. I think it's useful to distinguish the "official" argument from the analogies (like the watch analogy) that are usually used to support it. Specifically, I think that this is a useful format for assessing the argument. (There are a number of ways that the argument can be criticized, and I think the distinction between the "official" argument and the analogies can help us see some of these different criticisms.) 

So let's turn to the assessment of the Argument from Design. To begin, let's focus our attention on the "official argument". (We'll puzzle over the watch analogy below.)

Remember our discussion of arguments. If you'll recall, there are two ways of objecting to an argument. You can either question the truth of one or more of the premises (questioning the "soundness" of the argument) or you can attack the reasoning (questioning the "validity" of the argument).

The reasoning in the official argument is valid. If those premises are true, then the conclusion must also be true. But are those premises true? Let's look at each one in turn:

Premise 1. Premise 1 is a statement of the "principle to the best explanation". As I mentioned in class, there are some reasons for questioning this premise. However, for our purposes, I think we should just give this one to the proponent of the Argument from Design. The principle does have a good deal of plausibility. And as we will see, there are plenty of other possible objections to the Design Argument.

Premise 2. Premise 2 states that we observe "complex harmony" in the universe. The strength of this claim rests on the specific examples cited. (In class, I showed part of a video on BATS! to motivate this idea.) To be convincing, the proponent of the Design Argument needs to point to examples that really do cry out for an explanation

Premise 3. Premise 3 is the crucial (and most questionable) premise of the argument. This premise states that the "complex harmony" that we find in the universe is best explained by the presence of a designer. But we might question whether God’s existence provides the best explanation of what we observe in the universe.

First, we might raise some general worries about this claim. More precisely, we might question whether it really supports the explanation that the theist really wants to give. For example, most theists want to say that there is one single God, and that he presently exists. But how could either of these claims be established on the basis of a Design Argument. To make use of the watch analogy, most watches are designed and manufactured, not by a single person, but by a team of people. And of course, I have no way of knowing whether the designer of the watch is still alive. (A more serious worry along these lines comes up when we look at the Problem of Evil.)

Second, as a more substantial objection, we could question the claim that God’s existence provides the best explanation of what we observe in the universe on a case-by-case basis. That is:

Depending on what examples of “complex harmony” we look at, we might very well come up with rival explanations.
As an example I discussed in class, Darwin's theory of natural selection provides a quite elegant explanation of the "complex harmony" we found in the BATS! video. The point is that Darwin's theory provides a rival, and perhaps superior, explanation than the claim that the universe had a designer.

Questioning the Analogy

Remember, the Official Design Argument is often strengthened by appealing to the watch analogy. But, as I described in class, there are a couple of ways we might question any instance of analogical reasoning.

One way to question the reasoning is to question the analogy itself. That is, we might question whether the case of the universe is really that similar to the case of the watch. Notice, there are several disanalogies between the two cases. In class, I focused on two disanalogies:

The preceding two points both show ways in which the two cases (the universe case and the watch case) are dissimilar. But remember, to block an argument by analogy it isn't enough to simply point out some differences, you need to show that these differences are relevant to the conclusion drawn in each case.

(I think this is a deep and interesting issue. Are the cases relevantly disanalogous for the reasons given above. Could the example be modified to reinstate the analogy? These are questions that you might think about as a possible term paper.)