We saw that versions of the cosmological argument try to show that the existence of God is required to explain very general features of the universe - e.g. that things change, or that things come into and go out of existence. The design argument focuses on more specific features of the world to try to show that it must have, or most likely, came into existence as a result of the activity of an intelligent God.
The selection from Paley begins with the posing of a problem:
“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 for ever; ...But suppose that 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?”
Paley immediately offers an answer:
“For this reason, and for no other ...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.”
Paley then goes on to describe the ways in which the parts of the watch serve the purpose of keeping time, and illustrates the point that had even one part been slightly different, the watch would not have served this purpose. Having described this, he then goes on to conclude:
“This mechanism being observed ...the inference, we think, is inevitable, that the watch must have had a maker: that there must have existed, at some time, and at some place or other, an artificer or artificers who formed it for the purpose which we find it actually to answer; who comprehended its construction, and designed its use.”
Paley goes on to claim that we would make this inference even if the watch occasionally malfunctioned, if there were parts of it we could not understand, if we had never seen a watch before, etc. Paley concludes that it would be irrational to observe the watch and not infer that it had an intelligent maker. “Yet,” he concludes,
“This is atheism: for every indication of contrivance, every manifestation of design, every which existed in the watch, exists in the works of nature; with the difference, on the side of nature, of being greater and more, and that in a degree which excels all computation.”
The conclusion is obvious: just as we should conclude that the watch was created by an intelligent designer, so we should conclude that the world was created by an intelligent designer. To be an atheist is to commit the same kind of mistake as is made by someone who finds a watch on the heath, and concludes that it has always been there.
The design argument employs a form of inference known as inference to the best explanation.
This is different than the kinds of inferences we have discussed so far. So far, we have focused on deductively valid inferences, like
| 1. | This sweater is green. |
| 2. | If this sweater is green, then this sweater is my favorite color. |
| C. | This sweater is my favorite color. |
We have seen that to say that an argument is deductively valid (or just ‘valid’) is to say that the truth of the premises guarantees the truth of the conclusion: it is impossible for the premises to be true and the conclusion false.
But consider the kind of argument that Paley seems to be giving:
| 1. | The watch is so constructed that each of its parts serves the purpose of the watch. |
| 2. | The best explanation of the fact that the watch is so constructed that each of its parts serves the purpose of the watch is that the watch had an intelligent designer. |
| C. | The watch had an intelligent designer. |
Is this argument valid? Does this show that there is something wrong with Paley’s argument, or that some arguments can be good without being deductively valid?
The role of inference to the best explanation in science.
It is natural to object to Paley’s argument not on the grounds that it is an instance of inference to the best explanation, but rather on the grounds that modern science provides us with better explanations than does religion. For example, in a discussion which goes beyond the selection assigned for class, Paley discusses the design of the eye, and how it is more finely tuned and well suited for its function than even a watch. But can’t we explain the design of the eye in terms of the theory of natural selection, without ever mentioning an intelligent designer of the eye? And isn’t this explanation better, in the sense that it is better supported by evidence?
Paley says some things which are relevant to assessing this objection, in his discussion of the discovery of a watch with the power of replicating itself:
“The question is not simply, How came the first watch into existence? which question, it may be pretended, may be done away with by supposing the series of watches thus produced from one another to be infinite ...This perhaps would have been the state of the question, if nothing had been before us but an unorganized, unmechanized, substance, without mark or indication of contrivance. ...But that is not the question now. ...the question which irresistibly presses upon our thoughts is, Whence this contrivance and design?”
In terms of the evolutionary objection, Paley’s response might be: perhaps you can explain the human eye in terms of evolution; but how can the evolutionary process itself be explained?
Why this is not a satisfactory response.
Contemporary versions of the argument from design are constructed to be immune from this kind of objection. What is needed is to find some kind of natural phenomenon which can be (best) explained by positing an intelligent designer, and cannot be explained by the theory of evolution or any other scientific theory.
The example of the “fine-tuning of the universe.”