Problems with “Similarity” in the Design Argument
The Design Argument uses the premise that “The universe resembles human artifacts” (e.g. a watch).
From this, it analogically reasons to the (probable) existence of a universe-designer, since human artifacts have designers.
But this inference is potentially problematic, due to the vagueness of the universe “resembling” or “being similar to” a watch.
Suppose we are very strict about what is similar to my watch, so that only another watch could be similar to mine. Then, if the Design Argument is suggesting that the universe is similar to my watch, it is obviously suggesting something false.
On the other hand, suppose we are more liberal about what is
similar to my watch. Then, the universe could be like my watch—but so could
many other things. Thus, the planet Jupiter is similar to my watch in that both
are smaller than the sun, both are not bananas, both can be viewed through a
telescope, both existed yesterday at
But when we are this liberal about what is similar to my watch, we cannot (with any confidence) infer properties of something, on the basis of this “similarity.” After all, it would be obviously be wrong-headed to infer that Jupiter has a minute-hand, just like my watch. That’s not even *probable*.
Suppose, then, we tried to specify more precisely how a watch and the universe are similar. We could at least observe that they both have a “design.”
But remember, we cannot automatically infer the existence of a designer from a design…that’s what evolution casts doubt upon.
Moreover, it’s not obvious that having a design makes it more probable that there is a designer. All kinds of designs show up in the universe, but in many cases, it’s doubtful that the presence of a design evidences someone who designed it (e.g. ocean waves leaving a design in the sand).
We cannot fix this problem by supposing that the universe and my watch are similar because they both have a designer. That employs circular reasoning, since we are trying to argue to the conclusion that the universe has a designer.
Suppose, instead, we highlight that the universe and my watch are similar in having a relatively complex design. Accordingly, we might claim that if a design is sufficiently complex, it probably resulted from a designer, rather than random forces.
But it is also not clear why we should believe this last claim. The human brain, for example, has an extremely complex design (the design is so complex that we are very far from fully understanding it). Yet if evolutionary theory is right, this complex design could occur without the presence of a designer. (Our brain is designed how it is, because those of our species who didn’t have this complex design were less likely to survive and reproduce.)
Now it may be true that complex designs tend to come from a designer. But thus far, we do not seem to have sufficient reasons for believing this. For all we know, most complex designs might occur without a designer, like the evolved human brain.
The upshot is that we seem to lack sufficient reason for believing that watches and universes are similar in the appropriate ways. But if that’s so, then we cannot appeal to some similarity between the watch and the universe to infer the (probable) existence of a God. That doesn’t mean there isn’t a God who designed the universe. But it does mean that we have no reason to believe this, at least not yet.