The problem of evil and inference to the best explanation

The upshot of our discussion so far is this: there is some unclarity in the idea of harmony, the idea that the universe displays a mutual adaptation of parts.

size=2 color=black face="Times New Roman">We have also seen, however, that Cleanthes' argument relies on something very like induction, which Hume elsewhere subjected to such powerful criticism. Perhaps, then, we should draw the conclu­sion that the argument from design is better construed as a form of scientific hypothesis. It is suggestive, for example, that Isaac Newton, the great physicist, was among the most prominent devel­opers of the argument in the seventeenth century, and Hume called Cleanthes' position “experimental theism.” So we might want to examine whether the hypothesis that the universe was created by a divine intelligence could be established as reasonable on the same sorts of grounds as other scientific theories. We could, for example, try to reconfigure experimental theism in Popperian terms. Or we could propose that God's existence was the best explanation of all the available data.

Popper himself would have objected to the view that experimen­tal theism was a scientific theory, because the hypothesis in question is not a set of laws but a claim about the existence of a particular individual. Real theories, on Popper's view, make universal claims— that is why they can be falsified. They are universally quantified conditionals, whose form is

U: For all X, if X is F, then X is G,

not existential claims of the form

E: There exists an X that is F and G.

A single F that isn't a G falsifies U.

But this is a rather weak objection against the idea that the claim that God exists is a scientific hypothesis, I think, since whether or not it is a theory, it is surely a hypothesis. And, in any case, scientists do, of course, postulate the existence of particular things. The outer planets were originally postulated to explain perturbations in the paths of other celestial bodies; pathologists postulate the existence of new disease organisms. In the course of arguing for these exis­tence claims, they draw on laws and on known facts about other par­ticular things. But the postulation of God is rather unlike these stan­dard existential hypotheses, because it is meant to explain not particular things in the light of general laws but everything, includ­ing the fact that there are any laws of nature at all.

So let us explore briefly the question whether postulating the existence of a creator God provides the best explanation of the total­ity of the evidence available. Answering that question depends, as usual, on what conception of God you are proposing. Philo raises objections to Cleanthes' experimental theism that rely, in effect, on just such a consideration.

At the beginning of the tenth of the Dialogues, the three philoso­phers discuss the great amount of suffering and misery there is in the world. Cleanthes entertains the possibility (which, as I men­tioned in 3. 7, had actually been proposed by Leibniz) that this is an illusion—that, in fact, this is “the best of all possible worlds.” But Philo pretty quickly persuades him that this is not a plausible empir­ical claim.

Is he willing to prevent evil, but not able? then is he impotent. Is he able, but not willing? then is he malevolent. Is he both able and willing? whence then is evil?

This argument is offered, then, against those theists who claim, like traditional theologians, that God is omnipotent, omniscient, and perfectly good. Traditional theologians held that God could do anything that was logically possible, that he knew everything that happened in the universe, and that he would never do what was morally wrong. Philo is arguing that this is not consistent with the existence of evil.

Now, as the American philosopher Nelson Pike has correctly pointed out, this argument assumes that “an omnipotent and omnis­cient being could have no morally sufficient reason for allowing instances of suffering.” And many Christian theologians have denied this. They have argued, for example, that without free will our actions would be morally worthless, and that if we have free will, then the suffering that is caused by our exercise of it is not some­thing that God does. What it is for us to have free will is itself a sub­stantial philosophical question, which I will discuss in 9.10. But the argument here will go something like this:

In order for the world to be good, we must be free.

For us to be free, God must not interfere in our choices.

So: If we choose to cause suffering, he can only intervene at the cost of depriving us of our freedom, which is, in itself, a good.

If a world without both freedom and suffering would be worse than a world with both of them, then the existence of suffering caused by freedom would be consistent with God's being perfectly good.

Clearly, these are difficult questions on which many people, both religious and nonreligious, are divided. I mention them here to illus­trate the fact that once a moral conception of God is assumed, the question whether or not postulating his existence provides the best available explanation of all the data may lead one to consider the metaphysics of morality as well as the degree of (nonmoral) order in the world. Not only is the totality of the evidence vast—anything that happens is potentially relevant—but it also requires both moral and nonmoral judgment. Furthermore, particularly since the Reformation, many Christians have said that they experienced a direct encounter with God in prayer, maintaining, in effect, that they are acquainted, in Russell's sense, with him. So different peo­ple think they have access to very different kinds of data. It is not surprising, I think, in these circumstances, that “Is there a God” and “What is God like?” are not questions on which there is consensus either within or outside philosophy. Perhaps, then, that provides some support for the view that one way of understanding the argu­ment from design is, indeed, as a proposed inference to the best explanation.

8.13