Philosophers have often pondered which character represented Hume’s own position in his Dialogue Concerning Natural Religion. I want to argue that both Philo and Cleanthes are the mouthpiece for Hume’s own position. Let’s start by looking at how this is true for Cleanthes.

A superficial reading of the dialogue will almost inevitably lead us to the conclusion that Philo has won the argument hands down. After all, all of Cleanthes’ arguments are answered in clearest logic by Philo. However, a closer look, informed by a knowledge of Hume himself, suggests the possibility that this may not be the case.

Throughout Hume’s writings he was always careful to draw a distinction between what he believed versus what could be proved through reason. For example, although he argued that we could have no knowledge of causal laws – since all we have is an impression of one event followed by another event – nevertheless he still believed in cause and effect.  Similarly, though we cannot have direct sensory input concerning the self – since what we describe as our ‘self’ is merely a bundle of “different perceptions which succeed one another with inconceivable rapidity and are in a perpetual flux and movement” – nevertheless Hume said he still believed in the self. To understand anything about Hume, one must appreciate this tension between the beliefs of common sense versus philosophical skepticism. Early on the dialogue Philo/Hume acknowledges that his kind of skeptical philosophy is so often at variance to common sense.

How does this help us in understanding the dialogue? In Part XII of the dialogue, after we would have thought all of Philo’s objections would have left the argument from design in total shreds, Philo shocks us by acknowledging that the design argument has an irresistible attraction and cannot be easily dismissed. He even goes so far as to ask whether it were “possible for him [God] to give stronger proofs of his existence, than what appear on the whole face of Nature?”  Philo urges that God’s artifices are made so plain that it strikes even the most stupid and careless of thinkers. Philo then explains to Cleanthes that it is precisely because he knows he cannot corrupt the principles of any man of common sense that he is so uncautious when discoursing on natural religion. This suggests that because the evidence of a Designer is so firmly embedded in our natural instincts and common sense, Philo had no scruples in what he put forward precisely because he knew no man of common sense would take him seriously! In connection with this, one remembers how early on in the dialogue Pamphilus says that Philo appeared to be “somewhat between jest and earnest” and later on to be “a little embarrassed and confounded…”

Philo can be seen as agreeing with Cleanthes on a gut level, and then responding on another level in his attempt to demonstrate the insufficiency of translating that instinctive belief into racionation.

So to return to the question of which character represents Hume, I would like to suggest that Hume’s own ideas are represented by both Philo and Cleanthes: Cleanthes represents Hume’s natural irresistible instinct while Philo represents his rationality. The philosophical conflict between Philo and Cleanthes is a powerful representation of the psychological conflict within Hume himself, and the dichotomy that his radical empiricism inevitably led to.

But is this disjunction between feeling and reason necessary? Does the argument from design perhaps have more rational support than Hume allows?

Throughout the dialogue the arguments of Cleanthes and Demea are subjected to the utmost scrutiny by Philo’s unrelenting mind.  As a consequence, it is easy to gloss over and not recognize the fallacies in Philo’s own arguments.  However, such fallacies are numerous.  Let’s jump right into the argument from analogy to consider the main grounds for Philo’s objections.

Cleanthes had argued that because the design of the world bears resemblance to the design of human products, such as a watch or a house, the universe must have an intelligent Designer just as human artifacts have an intelligent designer. Since the effects are similar the causes must likewise be similar. Philo had attempted to show, in his rejoinder, that this argument from analogy is weekend to the degree of difference between the two cases. As he says, “whenever you depart, in the least, from the similarity of the cases, you diminish proportionably the evidence; and may at last bring it to a very weak analogy…”

In other words, the statement that one effect is like another effect, and therefore must have a similar cause, is weakened in direct proportion to the difference between the two objects in question. After having experienced the circulation of blood in some human creatures there is no difficulty inferring that it takes place in other humans, but it would be presumption to conclude from this that the circulation is the same in frogs and fishes.  Now in the case of human artifacts vs. the universe, the dissimilarity between the cases is so extreme and that the argument is completely invalid, according to Philo. We have no experience of universes being created and therefore it is a completely unique case and all attempts to compare it to other observable phenomena run into the ground. “Does not the great disproportion bar all comparison and inference?” he asks. For all we know matter may contain within itself the source of its own origination as does mind.

One of the flaws in the above argument is this. The argument from analogy simply does not hinge on the similarity the universe has to objects of human invention but, rather, only those properties of the universe that it shares in common with such objects, notably the properties of design and order.  In relation to such properties it is not true that there is a great dissimilarity between the order of the universe and the order of, say, a watch or a house, for both are completely similar in the abstract properties of order and non-chaotic-ness. All the other differences that Philo sets forth to strengthen the dissimilarity are irrelevant in this respect.

Let’s put the matter another way. Suppose that we’re talking about the tallest lady in Idaho, who in relation to her height is unique to anyone else, but in relation to her mortality is the same as everyone else. It would not do to say that the dissimilarity in height prevented us from drawing an analogy about her mortality. In the same way, neither is it rational to say that the dissimilarity between the universe and human objects prohibits us from making rational inferences concerning those properties in which they are not dissimilar, such as the arrangements of means to end’s and the absence of chaos. Yet Philo’s argument necessitates that where there are properties that make the universe unique from objects of human origination, we are unable to draw conclusions concerning those properties in which it is similar. If such a principle is accepted then it would entail that we could never make inferences about a totally new culture or infer that an utterly new and unique object in that culture was designed. The fact that the universe or some other object is unique does not rule out the possibility that it has properties in common with other objects, including some of the universe’s parts.

Philo argued further that even if the argument from analogy is established, it entails us to conclude a Designer to the universe similar to man on Cleanthes’ principle that similar effects prove similar causes. As Philo points out, this would undercut God’s infinitude, and could be taken to imply, for example, that God is corporeal. J.P. Moreland has argued otherwise in his Scaling the Secular City. Moreland points out that when one postulates an explanatory entity, we should attribute only to the entity that which is necessary for the explanation. For example, when we explain the design in human machines by postulating a human designer, it is the intellect of the designer that explains the design of the machine and not his corporeality. Similarly, all human artifacts have the property of coming from intelligence and the property of coming from being 93 million miles away from the sun. If we were to find artifacts on another planet, only the first property would be relevant. In the same way, the argument from analogy supports a similarity to human intelligence but not a similarity to humans in any other way.

Philo was half in jest when he put forward ideas such as the universe being a vegetable or an animal, in an attempt to work a reductio ad absurdum on Cleanthes’ argument. However, it is not be overlooked that these humorous suggestions merely push the problem away one level and do not offer an adequate substitute to design, for whichever state of affairs may have preceded the conditions in which the universe now exists – whether it be that a comet has planted a seed that grew into the universe, or the universe is the product of germination, or the universe is an animal with an entire pedigree of parents – it still has the properties relevant to the design argument.  The only way to escape this necessity would seem to be to suggest, as Cleanthes did in response to Demea’s reworking of medieval cosmological arguments, that the universe is an effect of an infinite regress of causation. By suggesting that the universe has existed for all eternity, Hume eliminates the need to find a first cause, “since that relation implies a priority in time, and a beginning of existence…”

The supposition that the universe had no beginning, however, lands us with multitudinous difficulties. The conditioned can never arrive until the conditions are complete; if those conditions are infinite then they can never be complete (just ask: one could never reach the top of an infinite set of stairs no matter how long one climbed?). Now the conditions on which present cause and effects exist is that all the past causes and effects have been completed. It follows that if those conditions are infinite (that is, if the past series of cause and effect recedes infinitely into the past), then they can never be complete and we could never have reached the present moment. If this is not enough to convince one of the absurdity of infinite regress, in The Kalam Cosmological Argument, William Craig has employed mathematical set theory to show that an actual infinite is a purely theoretical concept and can have no relation to the real world; hence, the attribution of infinity to the finite series of past events is logically absurd. One such absurdity can be seen in the fact that an actual infinite, by definition, cannot be added to, yet if the past series of events forms an actually infinite then each new moment in time is adding to that infinite, which is impossible. Since, by definition, one cannot traverse an actual infinite, the past series of events cannot stretch backward to infinity otherwise we would never have reached the present moment. (This argument only applies to properties within a time sequence. Thus, it does not bare relation on the infinity of God unless it were first assumed that God’s existence also flows in the time stream of past, present and future. But such an assumption is questionable.)

Such considerations, in ruling out the possibility of an infinite regress, establish that the universe must have had a beginning and, consequently, strengthen Demea’s argument for a First Cause which both Cleanthes and Philo so casually dismiss.

Another problem is Hume’s epistemological inconsistency towards the end. Hume argues that as regards knowledge of the deity we struggle with objects the “too large for grasp”, “are like foreigners in a strange country,” who “know not how far we ought to trust our vulgar methods of reasoning” and we cannot hope to achieve knowledge of God’s nature. Yet at the end of the dialogue Philo criticizes doctrines such as traditional conceptions of the afterlife, popular conceptions of God, etc. To know God is to worship Him, quotes Hume, whereas all that traditional forms of worship have achieved is to make one’s life miserable and to make men live under the burden of imaginary terrors. In response to this I only ask: where has Hume’s empiricism so conveniently disappeared to? Hume had spent the entire dialogue up to this point arguing for an agnostic approach to God, which hardly seems consistent with saying it is an absurdity to suppose the deity to be possessed of human-like passions. Such a statement  – whether true or false – is, after all, a truth claim about the very nature of the deity; but Hume has already pronounced that the nature of the deity is off-limits to our minds. Similarly when Philo asserts that popular conceptions of the afterlife are misplaced, one is tempted to use his earlier argument against him and ask whether he had in fact died and come back in order to observe this fact, just as he had asked Cleanthes whether universes had been formed under his eye when trying to disprove the argument from design.

But then, for all Hume’s strong points, consistency was not one of them.