One way of proving God’s existence is to point to disruptions in the natural order: only God could cause a miracle. Another way is to point to the cause of the natural order: only God could produce an orderly universe. In the previous section, Hume took on the first sort of argument. In this section, he takes on the second.
This section grants, for the sake of argument, the central claim of natural religion, that we can infer God’s existence from the order of the natural world. It denies that we can infer God has two qualities that are commonly attributed to him: providence and justice. If he succeeded, he would have raised a strong challenge to the point of organized religion and helped make the case for the possibility of morality among atheists.
In the last paragraph, Hume argues that we shouldn’t believe the argument from design in the first place. That is, he argues that we can’t legitimately move from observations of order in the world to the conclusion that an intelligent designer created that order.
“Epicurus’s” argument works by first granting that we can infer the existence of a designer on the basis of the evidence of order in the observable world. “Epicurus” denies that we can infer that the designer has some qualities that God is thought to possess. In particular, the argument holds that we cannot infer that God is provident or just.
The argument relies on a rule of reasoning that tells us what we can infer about unobserved causes of observed effects: we cannot infer more than is strictly necessary to bring about the effect. We can see that the world is imperfect. So what can we conclude about God? No more than the rule of reasoning, when combined with our observations of the world, permits.
Hume raises some interesting objections against the argument that he, er, his “friend” imagined Epicurus making. The discussion of the half-finished building, for instance, is quite interesting.
There were several sharp replies to this objection, all of which Hume probably would have accepted. Robert noted that we have no experience of the divine designer whereas, by contrast, we have a lot of experience of human builders. Alex noted that we have no experience of universes, other than this one, on which to base a conclusion that this one is only half finished. And Zach added that it doesn’t make any sense for God to have left the universe half finished. Human builders are finite creatures, so their buildings are incomplete for quite some time. But God’s power is infinite. So why would his universe be incomplete for any period of time?