Parts IV through VIII of the Dialogues, comprising a bit more than a quarter of the text, consist of a very deep attack on the ordinary religious beliefs of Judaism, Christianity, and Islam [none of which is named, of course], followed by a boisterous and increasingly uproarious send-up of the Argument from Design, the very last portion of which is, in a way, actually a quite brilliant anticipation of the theory of evolution.
Once again, Hume keeps things afloat by apportioning bits of his argument first to Cleanthes, then to Philo, and then even to Demea. The first question concerns the nature of God. The problem, to put it in a nutshell, is that if we want to describe God as infinite [in power, in knowledge, in length of existence, in degree of benevolence], then we cannot also claim that He is recognizably a person who loves, desires, cares, hopes, rages, forgives, damns, or saves, as the Revealed texts of the three Adamic religions teach. This was, of course, an old problem, long recognized by religious philosophers of the Western tradition, over which they struggled endlessly.
The easiest way to grasp the problem is to remind ourselves of Aristotle's analysis of purposive action as a movement from potentiality to actuality. Such a movement implies an initial lack or imperfection, inasmuch as potentiality is less real, less perfect, than actuality. But assuming the correctness of that analysis, as philosophers did for two millennia, it is obvious that God cannot act, in this sense of the term, for that would require that he be at some point less than perfectly actual, which is contrary to the claim that God is infinitely perfect [or, to put it somewhat differently, that God is infinite perfection.]
Thus, for example, God's omniscience entails that He knows, from all eternity, everything that is true, including what each individual person will do at each moment in his or her life. He cannot ever come to know something, for that implies the actualization of some potentiality, which is to say a movement from lesser to greater perfection [of knowledge.] It is this implication of the assertion of God's perfection that led Calvin and Luther to embrace the doctrine of Predestination [with the necessary corollary that nothing we do can ever earn salvation -- our actions at best reveal whether we have, from all eternity, been predestined for salvation. Hence the obsessive self-examination of the early Puritans, in their religious diaries.]
We see here once again the conflict between the Graeco-Roman philosophical tradition, deriving from Plato and Aristotle, which teaches that there is an impersonal Prime Mover or First Cause, required by the metaphysics of being, and the Adamic tradition, which preaches a personal God, a God of anger and of mercy, a God of salvation and damnation, a God with whom worshippers can have a personal relationship of reverent prayer. [I hope everyone understands the term "Adamic," which is used to describe Judaism, Christianity, and Islam, all of which accept the story of Adam and Eve in Genesis, and the various consequences that flow from it.]
Hume puts the strongest statement of this argument in the mouth of Cleanthes, who is represented as arguing against Demea's ostensibly devout embrace of the unknowability of God. Here, as they say in the blogs, is the money quote. Cleanthes is speaking.
"A mind whose acts and sentiments and ideas are not distinct and successive, one that is wholly simple and totally immutable, is a mind which has no thought, no reason, no will, no sentiment, no love, no hatred; or, in a word, is no mind at all. It is an abuse of terms to give it that appellation, and we may as well speak of limited extension without figure, or of number without composition."
Hume keeps the discussion going for some while, allowing Philo to expand on the implications of what Cleanthes has said, but here, as elsewhere, the elaboration does not strengthen the argument so much as present it in many variations, so that the less alert reader will not make the mistake of supposing that a slight alteration in the statement of the religious position will somehow suffice to avoid the refutation.
Now Philo launches into an extended take-down of the Argument from Design. Although I cannot of course be certain, my guess is that the readers of this blog can for the most part be described as non-believers -- perhaps not insistent atheists, ever ready to launch an argument with the devout, but probably not regular church-goers. You may therefore not have spent endless hours listening to sermons, or reading religious literature, in which some version of the Argument from Design is articulated. Serious believers do really see evidences of God's handiwork in virtually every corner of the experienced world -- in the orderly progression of the planets about the sun, in the miracle of childbirth, in the beauty of a butterfly, in the majesty of a thunderstorm. These are not merely familiar literary tropes; they are the way in which believers experience the world.
All of these beliefs, Hume suggests, and the arguments put forward to express or sustain them, commit the same elementary mistake of assuming what is to proved, of begging the question, to use that oft-misused expression correctly. Every version of the Argument from Design begins with some example of the intentional fitting of ends to means, of the physical arrangement of a bit of matter to subserve some human purpose, then argues that some part of the natural order, or indeed of the entire universe, resembles these examples of intentional adaptations, and finally leaps to the conclusion that the cause of these observed adaptations is precisely the God preached in sermons and memorialized in Revealed Texts.
Over the course of four Parts, Hume pours out arguments with seemingly endless imagination, but they all have the same logical structure. Our causal inferences rest of our observations of repeated conjunctions of resembling instances. They are no more certain than the sets of observations on which they are based. Now, if we set to one side our already well established religious beliefs, which we have taken from divine texts or countless Sunday sermons, what do we in fact find?
Well, many of the most intricately designed objects that we encounter, such as watches or locomotive engines, are the product of the joint efforts of many purposive agents working together -- architects, or designers, or machine tool craftsmen, or jewelers, or glassmakers. So why may we not infer that the arrangements we see in nature are also the products of many gods working together? Most well-designed purposively arranged objects are the end products of long periods of experimentation, during which there are failures and partial successes before the artisans finally get it right. So, may we not conclude that this world is actually only the latest in a long series of failed attempts apprentice gods, working under the direction of master world builders? Quite the most miraculous examples of the fittingness of means to ends can be found in the internal arrangements of living things. An infant is a more remarkable assemblage of interacting parts than even the solar system. So perhaps this world emerged from the womb of a mother world, impregnated by a father world, who together gave birth to this world in which we live. And so on and on Hume goes, spinning ever more fanciful hypotheses, each of which, Philo insists, is as well supported by our observations and causal reasonings as the traditional Bible story.
In Part VIII, Hume advances a new and much more interesting argument, derived in part from the speculations of the ancient atomists, with whose teachings of course eighteenth century philosophers were quite familiar. "Instead of supposing matter infinite, as Epicurus did," Philo suggests, "let us suppose that it is finite. A finite number of particles is only susceptible of finite transpositions; and it must happen, in an eternal duration, that every possible order or position must be tried an infinite number of times. This world, therefore, must with all its events, even the most minute, has before been produced and destroyed, without any bounds or limitations. No one who has a conception of the powers of the infinite, in comparison to the finite, will ever scruple this determination." So there need have been no intelligence at work in the creation of this world. Mere chance will explain how such remarkable order, and fittingness of means to ends, should have come about.
What is more, Philo goes on, inasmuch as our present world exhibits what today physicists would call homeostasis, which is to say a tendency to maintain order once it is achieved, perhaps the universe went through a vast series of arrangements until, by sheer accident, an arrangement came about that had this tendency to sustain itself. This would be sufficient to explain the seeming stability of the world order as we observe it.
Finally, at the end of Part VIII, Philo puts forward an argument that strikes me as a fascinating anticipation of the theory of natural selection advanced a century later by Darwin and Wallace. Here is the passage:
"It is in vain, therefore, to insist upon the uses of the parts in animals or vegetables, and their curious adjustment to each other. I would fain know how an animal would subsist unless its parts were so adjusted? Do we not find that it immediately perishes whenever this adjustment ceases, and that its matter, corrupting, tries some new form? It happens indeed that the parts of the world are so well adjusted that some regular form to this corrupted matter; and if it were not so, could the world subsist? Must it not dissolve, as well as the animal, and pass through new positions and situations till in great but finite succession it fall, at last, into the present or some other order?
I am, of course, a great partisan of Hume, and am quick to find in his writings intimations of all manner of ideas that have subsequently gained favor, but I must say that I find here a hint of the so-called Anthropic Principle advanced by Stephen Hawking.