In this section, Philo points out another problem with the design argument: every scientific advance makes the argument less plausible by showing us how absolutely unique and awe-inspiring the universe is. These scientific discoveries show that the universe is unlike anything human beings have ever made. By the argument by design, then, the universal cause must be vastly different from mankind.
After making this small point, Philo begins his third major line of attack. He points out that there is not enough evidence in nature to allow the empirical theist to draw the conclusions he wishes to draw. The empirical theist, as a believing Christian, wants to be able to conclude from his design argument that God is infinite, perfect, one in number, and immaterial (that he is not made of physical matter). But given the evidence he has to go on, he cannot conclude any of these things. When reasoning from effects to causes, we are only entitled to infer as much as the effect warrants.
First, we cannot possibly conclude from the evidence that God's attributes are infinite in any way because, so far as we can tell, the universe is not infinite. Since the universe is not infinite, there is no plausible basis on which to conclude that whatever caused the universe is infinite. Therefore, the design argument does not warrant belief in an infinite God.
Second, we cannot even conclude from the evidence that God is finitely perfect. For all we know our universe could be a lot better than it is; our universe might even be a lousy universe, compared to what it could be. And so our designer could be a lousy designer. Moreover, even if we knew our universe was a perfectly wonderful universe, that still would not allow us to conclude that our designer is a perfect designer. He could have gotten lucky with this project, he could have copied it from other designers, or else this could have been a final successful try after a string of failures.
Further, the evidence we have available to us cannot support the claim that there is only one God. There is nothing to prove that the creation of the universe was the work of one designer. In fact, if the universe is so closely analogous to works of human artifice, then we have good reason to think that the design of the universe was a group project performed by several deities, for many machines and systems are made by more than one person. And if, in fact, the design of the universe was the result of teamwork, it only further diminishes the amount of skill we need to assign to each individual deity. The design argument could just as easily lead us to posit that the cause of our universe was a pack of barely competent gods, as it could lead us to posit that the cause of our universe was a single all-powerful Deity.
Finally, if we take the analogy between God and man seriously, we can even infer that God's mind is contained in a body. After all, the mind of every intelligent designer we have ever experienced has been contained in a physical body. What reason do we have to believe that God's is not? Also, why not believe that gods are mortal and reproduce, if they are so similar to man?
Cleanthes fails to grasp the strength of this rebuttal and is unfazed by Philo's demonstration. In fact, he sees in it a concession: at least Philo is finally admitting that the universe is obviously designed. Of course, Philo is not admitting this; he is merely arguing that even if we could infer a designer, we could not infer the sort of designer that the theist wants to infer.
It is important to realize that Philo is not trying to claim in this section that Cleanthes' argument from design actually leads one necessarily to these heretical positions. He is only claiming that Cleanthes' argument does not provide any grounds on which to deny these positions. This is a severe problem for Cleanthes. His claim (the standard claim of empirical theism) is that we can come to know all about God from the evidence provided by the natural world. Philo shows, however, is that it is impossible to use the evidence provided by the natural world to come to any substantive conclusions at all about God's nature. The evidence as well supports the claim that God is anthropomorphic, simple, eternal, and incorporeal as it does the claim that God might be actually be a team of mortal and muscle-bound workmen who copied a great designer and created a barely adequate universe.
As always, it is helpful to compare this type of reasoning to a more familiar example from everyday life. Imagine that you see a man bench press 400 pounds. You could certainly conclude that this man is very strong. But you could not conclude that he is infinitely strong, or that there is nothing he cannot lift. All you can conclude, given the evidence, is that he is strong enough to bench press 400 pounds. When we reason from effects to causes, we are only justified in inferring what is necessary to explain the effect. All that is necessary to explain the effect in the case of the man is that he is strong enough to lift 400 pounds. All that is necessary to explain the effects in the case of the designed universe (assuming, for the sake of argument, that the universe was even designed) is that there be some intelligent designer or designers behind it. Any further conclusions are pure conjecture, with no basis in any evidence.