This section is concerned with arguments from design. These were the mainstay of what was called natural religion. Natural religion concerns what can be known about God on the basis of normal human inquiry. It is the view that we can know basic truths about God simply by examining the natural world. We can make inferences about God’s features in the course of explaining what we observe in the natural world.
Hume presents arguments meant to show that those who believe in natural religion cannot use it to justify their beliefs on two topics: God’s providence, or intervention into the world on our behalf, and the possibility of life after bodily death.
A subsidiary theme is that atheists, like “Epicurus” are safe. This is contrary to the view we saw in Grotius.
This is also an unstated theme of Hume’s moral philosophy. Hume offered an explanation of why people behave morally that is based only on their feelings. His explanation does not rely on God as the source of the moral rules. Nor does it rely on the fear of divine punishment as a motivation for moral behavior. If it is correct, athiests, having the same feelings as anyone else, are pretty much as safe as anyone else.
Update: Scientific American tackles the question of whether religious belief is good for a society. The answer? “The data are conflicting”. Humph. Science.
Natural religion does not depend on disruptions of the natural order to prove that there is a supernatural being. Nor does it depend on extraordinary faith, inspired by supernatural sources. Those are the two sources of religious belief taken up in the section on miracles. “Disruptions of the natural order” are miracles. They cannot have a natural explanation, being disruptions. So a supernatural being offers the only explanation for why they happen. Extraordinary faith is given at the end of the section on miracles in what looks to me like a patently insincere endorsement.
In the seventeenth century, and perhaps earlier, for all I know, natural religion was contrasted with Christianity. Natural religion was what anyone could know about God. But the purported truths of Christianity had been revealed only to some, through the Bible and/or the Church (which church was The Church was, of course, a subject of violent controversy).
Given the social prominence of the natural sciences and the rise of genuine atheism, natural religion took on a greater role in defenses of Christianity. You can see it especially in the reactions to Darwinism. For instance, those who hold that the diversity of life and the origins of human beings are evidence of an intelligent designer belong to this tradition. The President himself said that “both sides”, meaning intelligent design theory and modern evolutionary biology ought to be taught in school. I cannot say whether this is something he sincerely believes, of course. But the fact that he thinks there are two sides is evidence that natural religion is very much alive.
Hume’s strategy, as articulated by his friend in an imagined speech by Epircurus, consists in arguing that we can’t infer the existence of anything more perfect than the natural world on the basis of our experience of the natural world. Even if we grant that the order we observe in the world is evidence that there is an intelligent designer of the world, we can’t infer that the designer has particular qualities that go beyond what we observe.
Thus we can’t know that God is any more provident than the natural world is. The only evidence we have of God’s interventions on our behalf is the way things are. God may well be more caring than nature, but we can’t know that just by observing the natural world that, by hypothesis, God designed and created.
Nor can we infer the existence of a future state, that is, life after death, based solely on what we know of this life.
Two intesting things happen at the end. First, Hume presents an objection to these arguments which his friend answers. Second, Hume challenges all arguments based on design. By contrast, the section itself just challenged arguments that sought to establish a few particular points about God and his relationship to human life.