Hume's Dialogues Concerning Natural Religion (1779) Quick Review: The Issue: What can we know, by reason and experience alone, about the nature and attributes of the Deity? Dialogues Parts I-III: The Design Argument: Cleanthes' statement of the Design Argument: the world as a machine. Philo's critique: As an argument, the machine analogy fails. Our ideas reach no farther than our experience. Since we have no experience of the divine attributes, we have no idea of what God might be like, either.

Philo’s Explanatory Regress Challenge: Cleanthes’ argument presupposes that the world as we encounter it requires an explanation of some sort. More precisely: Ideal World  Material World But, “a mental world or universe of ideas requires a cause as much as does a material world or universe of objects" (p. 30). Another World  Ideal World  Material World Philo’s Challenge: “Have we not the same reason to trace that ideal world into another ideal world or new intelligent principle? But if we stop and go no farther, why go so far? Why not stop at the material world?” (p. 31)

Dialogues Part V: The "Inconveniences" of Anthropomorphism Cleanthes' Principle: "Like effects prove like causes" (p. 34). So, just as we can infer an intelligent human designer from well-made human artifacts, so too we can infer a perfect Designer from the perfect (machine-like) character of the world. Philo’s Principle: Fine, but our claims about the cause of any effect ought to be proportioned to the nature of that effect: "Now it is certain that the liker the effects are which are seen and the liker the causes which are inferred, the stronger is the argument. Every departure on either side diminishes the probability and renders the experiment less conclusive" (p. 34).

Thus (pp ): As the world itself in not infinite, we have no reason on this basis to ascribe infinity to any of the attributes of the Deity. As there are "many inexplicable difficulties in the works of Nature," we have no reason to ascribe perfection to the Deity. We know that many well-constructed human artifacts result not from intelligence, but from a long period of trial and error (cf. shipbuilding). Consequently, we need not consider the Deity to be especially intelligent. As many excellent human contrivances are the products of many people working together (cf. ships, buildings, cities), we have no reason to think that the Deity is unitary.

Human artificers are mortal, and renew their species by generation. So we have ample basis for believing the Deity (or deities) to arise by generation, of being gendered, and of reproducing as in humans. Human artificers all have physical bodies. So we ought to suppose the deities to have noses, ears, and to be corporeal. In summary, if Cleanthes' principle ("Like effects prove like causes" ) were to be taken seriously, the world might, for all we know, be only "the first rude essay of some infant deity," or "the work of some dependent, inferior deity," or "the production of old age and dotage in some superannuated deity" (p. 37).

Again, Cleanthes' Dilemma: Cleanthes can either: Take his experience of nature as his guide to the nature of the Deity, and be prepared to embrace all the anthropomorphic consequences (and more) enumerated above. Reject his experience of nature as a guide to the nature of the Deity, but admit that we have no other basis for inferring the attributes of the Deity, and hence be prepared to embrace complete mysticism (a la Demea), or theological skepticism (a la Philo). Either way, however, Cleanthes' attempt to justify the orthodox conception of God fails.

Philo’s Two-Pronged Strategy: (1) Show that Cleanthes’ inference to an Intelligent Designer having the traditional divine attributes is underdetermined by the data we have at our disposal. (2) Show that the world as we experience it is consistent with a plethora of other explanatory hypotheses (some of which might be even more plausible than Cleanthes’ Intelligent Designer postulate).

Dialogues Part VI: The World as an Animal(?) Philo: Cleanthes compares the world to a machine. But doesn't it as much (or more) resemble an animal? "The closest sympathy is perceived throughout the entire system: And each part or member, in performing its proper offices, operates both to its own preservation and to that of the whole. The world, therefore, I infer, is an animal; and the Deity is the Soul of the world, actuating it, and actuated by it" (pp ). Question: Why might Philo's comparison of the world to an animal (rather than to a machine) be fatal to Cleanthes' argument?

Dialogues Parts VII-IX: “Wild Conjectures” and Arguments A Priori Part VII: The Nature of the Deity (continued) Cleanthes: The world is (or is similar to) a machine, and hence suggests an intelligent Designer (p. 15). Philo: But in some ways it even more closely resembles an animal. So perhaps the Deity is the soul of the world, and the world is its body (pp ) Cleanthes: Nah, actually the world is more like a vegetable than an animal. And vegetables don't have souls (p. 41). Philo: But "If the world bears a greater likeness to animal bodies and to vegetables than to the works of human art, it is more probable that its cause resembles the former than that of the latter, and its origin ought rather to be ascribed to generation or vegetation than to reason or design" (p. 44).

Demea: "But how is it conceivable... that the world can arise from anything similar to vegetation or generation?" (p. 45). Philo's "panspermia" hypothesis (p. 45): If the world is like a vegetable, perhaps comets are interstellar "seeds". If the world is like an animal, perhaps comets are like eggs.

Demea: But these are "wild, arbitrary suppositions". "What data have you for such extraordinary conclusions? And is the slight, imaginary resemblance of the world to a vegetable or an animal sufficient to establish the same inference with regard to both? Objects which are in general so widely different; ought they to be a standard for each other?" (p. 45) Philo: Right! That's what I've been trying to tell you!!! "Our experience, so imperfect in itself and so limited both in extent and duration, can afford us no probable conjecture concerning the whole of things" (p. 45). "These words generation, reason mark only certain powers in nature whose effects are known, but whose essence is incomprehensible; and one of these principles, more than the other, has no privilege for being made a standard to the whole of nature" (p. 46).

Part VIII: More "Wild Conjectures" Philo's "Eternal Recurrence" Hypothesis: P1: A finite number of particles is only susceptible of finite transpositions. P2: In an eternal duration, every possible order of position must have been tried an infinite number of times. C: "This world... with all its events... has before been produced and destroyed, and will again be produced and destroyed, without any bounds and limitations" (p. 49).

Nietzsche’s Eternal Recurrence Doctrine "This life as you now live it and have lived it, you will have to live once more and innumerable times more; and there will be nothing new in it, but every pain and every joy and every thought and sigh and everything immeasurably small or great in your life must return to you- all in the same succession and sequence-even this spider and this moonlight between the trees, and even this moment and I myself. The eternal hourglass of existence is turned over and over, and you with it, a grain of dust." -- Friedrich Nietzsche, Thus Spake Zarathustra

Woody Allen on the Eternal Recurrence "I read all the great philosophers.... Socrates -- what does he know? He used to knock up little Greek boys. And Nietzsche, with his theory of eternal recurrence. He said that the life we lived we're gonna live over and over again the exact same way for eternity. Great. That means I'll have to sit through the Ice Capades again. It isn't worth it...." -- Woody Allen, Hannah and Her Sisters

Philo's Order Out of Chaos Hypothesis: Perhaps order arose naturally out of disorder by matter successively occupying relatively stable forms, which are then preserved, having "all the same appearance of art and contrivance which we observe at present" (p. 50).

Dialogues Part IX: A Priori Arguments Demea's Suggestion: "If so many difficulties attend the argument a posteriori... had we not better adhere to that simple and submlime argument a priori which, by offering us an infallible demonstration, cuts off at once all doubt and difficulty?" (p. 54) The Argument: "Whatever exists must have a cause or reason of its existence.... In mounting up, therefore, from effects to causes, we must... at last have recourse to some ultimate cause that is necessarily existent.... There is, therefore, such a Being -- that is, there is a Deity" (pp ).

Cleanthes' Reply #1: The arguments depends on a false assumption. "There is an evident absurdity in pretending to demonstrate a matter of fact, or to prove it by any means a priori. Nothing is demonstrable unless the contrary implies a contradiction. Whatever we conceive as existent, we can also conceive as non-existent. There is no being, therefore, whose non-existence implies a contradiction. Consequently there is no being whose existence is demonstrable" (p. 55). Cleanthes' Reply #2: Even if we accept that assumption, it still fails. "Why may not the material universe be the necessarily existent Being? We dare not affirm that we know all the qualities of matter; and, for aught we can determine, it may contain some qualities which, were they known, would make its non-existence appear as great a contradiction as that twice two is five" (p. 56).

Philo's "Mathematical Necessity" Argument: "[T]he products of 9 compose always either 9 or some lesser product of 9 if you add together all the characters of which any of the former products is composed.... To a superficial observer so wonderful a regularity may be admired as the effect either of chance or design; but a skilful algebraist immediately concludes it to be the work of necessity, and demonstrates that it must forever result from the nature of these numbers. Is it not probable... that the whole economy of the universe is conducted by a like necessity, though no human algebra can furnish a key which solves the difficulty?" (p. 57) "[I]nstead of admiring the order of natural beings, may it not happen that, could we penetrate into the intimate nature of bodies, we should clearly see why it was absolutely impossible they could ever admit of any other disposition?" (p. 57). Dismissal of all a priori arguments.