Thursday, June 10, 2004

Proving Plantinga's God-2

Some thinkers claim that none of this ought to be thought surprising or as requiring explanation: no matter how things had been, it would have been exceedingly improbable. (No matter what distribution of cards is dealt, the distribution dealt will be improbable.) This is perhaps right, but how does it work? and how is it relevant? We are playing poker; each time I deal I get all the aces; you get suspicious: I try to allay your suspicions by pointing out that my getting all the aces each time I deal is no more improbable than any other equally specific distribution over the relevant number of deals. Would that explanation play in Dodge City (or Tombstone)?

Others invoke the Anthropic Principle, which is exceedingly hard to understand but seems to point out that a necessary condition of these values of the physical constants being observed at all (by us or other living beings) is that they have very nearly the values they do have; we are here to observe these constants only because they have the values they do have. Again, this seems right, but how is it relevant? What does it explain? It still seems puzzling that these constants should have just the values they do. Why weren't they something quite different? This is not explained by pointing out that we are here. (a counterexample to Hempelian claims about explanation) Like "explaining" the fact that God has decided to create me (instead of passing me over in favor of someone else) by pointing out that I am in fact here, and that if God had not thus decided, I wouldn't have been here to raise the question.

Another approach:

Abstract:
We examine the question of whether the present isotropic state of the universe could have resulted from initial conditions which were "chaotic" in the sense of being arbitrary, any anisotropy dying away as the universe expanded. We show that the set of spatially homogeneous cosmological models which approach isotropy at infinite times is of measure zero in the space of all spatially homogenous models. This indicates that the isotropy of the Robertson-Walker models is unstable to homogeneous and anisotropic perturbations. It therefore seems that there is only a small set of initial conditions that would give rise to universal models which would be isotropic to within the observed limits at the present time. One possible way out of this difficulty is to suppose that there is an infinite number of universes with all possible different initial conditions. Only those universes which are expanding just fast enough to avoid recollapsing would contain galaxies, and hence intelligent life. However, it seems that this subclass of universes which have just the escape velocity would in general approach isotropy. On this view, the fact that we observe the universe to be isotropic would simply be a reflection of our own existence.

We shall now put forward an idea which offers a possible way out of this difficulty. This idea is based on the discovery that homogeneous cosmological models do in general tend toward isotropy if they have exactly the same escape velocity. Of course, such "parabolic" homogeneous models form a set of measure zero among all homogeneous models. However, we can justify their consideration by adopting a philosophy which has been suggested by Dicke (1961) and Carter (1968). In this approach one postulates that there is not one universe, but a whole infinite ensemble of universes with all possible initial conditions. From the existence of the unstable anisotropic model it follows that nearly all of the universes become highly anisotropic. However, these universes would not be expected to contain galaxies, since condensations can grow only in universes in which the rate of expansion is just sufficient to avoid recollapse. The existence of galaxies would seem to be a necessary precondition for the development of any form of intelligent life. Thus there will be life only in those universes which tend toward isotropy at large times. The fact that we have observed the universe to be isotropic therefore only a consequence of our own existence. 319

Spatially homogeneous models can be divided into three classes: those which have less than the escape velocity (.e., those whose rate of expansion is insufficient to prevent them from recollapsing), those which have just the escape velocity, and those which have more than the escape velocity. Models of the first class exist only for a finite time, and therefore do not approach arbitrarily near to isotropy. We have shown that models of the third class do in general tend to isotropy at arbitrarily large times. Those models of the second class which are sufficiently near to the Robertson-Walker models do in general tend to isotropy, but this class is of measure zero in the space of all homogeneous models. It therefore seems that one cannot explain the isotropy of the universe without postulating special initial conditions.. . . .

The most attractive answer would seems to come from the Dickie-Carter idea that there is a very large number of universes, with all possible combinations of initial data and values of the fundamental constants. In those universes with less than the escape velocity small density perturbations will not have time to develop into galaxies and stars before the universe recollapses. In those universes with more than the escape velocity, small density perturbations would still have more than the escape velocity, and so would not form bound systems. It is only in those universes which have very nearly the escape velocity that one could expect galaxies to develop, and we have found that such universes will in general approach isotropy. Since it would seem that the existence of galaxies is a necessary condition for the development of intelligent life, the answer to the question "why is the universe isotropic?" is "because we are here". 334

C. B. Colling and S.W. Hawking, "Why is the Universe Isotropic?" The Astrophysical Journal, March 1, l973

Here you had better look up Alan Guth , "Inflationary Universes: A possible solution to the horizon and flatness problems, Physical Review D, 23, 1981 347-356, and some other pieces mentioned by John Earman, "The SAP also Rises: . . . " American Philosophical Quarterly, Oct. l987

From a theistic point of view, however, no mystery at all and an easy explanation.

(F) The Naive Teleological Argument
Swinburne:
The world is a complicated thing. There are lots and lots of different bits of matter, existing over endless time (or possibly beginning to exist at some finite time). The bits of it have finite and not particularly natural sizes, shapes, masses, etc; and they come together in finite, diverse and very far from natural conglomerations (viz. lumps of matter on planets and stars, and distributed throughout interstellar space). . . . . Matter is inert and has no powers which it can choose to exercise; it does what it has to do. yet each bit of matter behaves in exactly the same way as similar bits of matter throughout time and space, the way codified in natural laws. . . . . all electrons throughout endless time and space have exactly the same powers and properties as all other electrons (properties of attracting, repelling, interacting, emitting radiation, etc.), all photons have the same powers and properties as all other photons etc., etc. Matter is complex, diverse, but regular in its behaviour. Its existence and behaviour need explaining in just the kind of way that regular chemical combinations needed explaining; or it needs explaining when we find all the cards of a pack arranged in order. EG 288

Newton: Whence arises all this order and beauty and structure?

Hume Dialogues: Cleanthes: Consider, anatomize the eye. Survey its structure and contrivance, and tell me, from your own feeling, if the idea of a contriver does not immediately flow in upon you with a force like that of sensation. The most obvious conclusion, surely, is in favour of design, and it requires time, reflection and study to summon up those frivolous, though abstruse objections which can support infidelity.

The idea: the beauty, order and structure of the universe and the structure of its parts strongly suggest that it was designed; it seems absurd to think that such a universe should have just been there, that it wasn't designed and created but just happened. Contemplating these things can result in a strong impulse to believe that the universe was indeed designed--by God.

(Hume's version may be very close to a wholly different style of "argument": one where the arguer tries to help the arguee achieve the sort of situation in which the Sensus Divinitatis operates.)

(G) Tony Kenny's style of teleological argument

(H) The ontological argument

I. Another argument thrown in for good measure.
Why is there anything at all? That is, why are there any contingent beings at all? (Isn't that passing strange, as S says?) An answer or an explanation that appealed to any contingent being would of course raise the same question again. A good explanation would have to appeal to a being that could not fail to exist, and (unlike numbers, propositions, sets, properties and other abstract necessary beings) is capable of explaining the existence of contingent beings (by, for example, being able to create them). The only viable candidate for this post seems to be God, thought of as the bulk of the theistic tradition has thought of him: that is, as a necessary being, but also as a concrete being, a being capable of causal activity. (Difference from S's Cosmo Arg: on his view God a contingent being, so no answer to the question "Why are there anything (contingent) at all?"

II. Half a dozen Epistemological Arguments

(J) The argument from positive epistemic status
Clearly many of our beliefs do have positive epistemic status for us (at any rate most of us think so, most of us accept this premise). As we have seen, positive epistemic status is best thought of as a matter of a belief's being produced by cognitive faculties that are functioning properly in the sort of environment that is appropriate for them. The easiest and most natural way to think of proper functioning, however, is in terms of design: a machine or an organism is working properly when it is working in the way it was designed to work by the being that designed it. But clearly the best candidate for being the being who has designed our cognitive faculties would be God.

This premise of this argument is only a special case of a much broader premise: there are many natural (nonartifactual) things in the world besides our cognitive faculties such that they function properly or improperly: organs of our bodies and of other organisms, for example. (Tony Kenny's design argument)

Objection: perhaps there is indeed this initial tendency to see these things as the product of intelligent design; but there is a powerful defeater in evolutionary theory, which shows us a perfectly natural way in which all of these things might have come about without design.

Reply: (1) is it in fact plausible to think that human beings, for example, have arisen through the sorts of mechanisms (random genetic mutation and natural selection) in the time that according to contemporary science that has been available? The conference of biologists and mathematicians ("Mathematical Challenges to the NeoDarwinian Interpretation of Evolution", ed. Paul Morehead and Martin Kaplan, Philadelphia, Wistar Institute Press); the piece by Houston Smith. The chief problem: most of the paths one might think of from the condition of not having eyes, for example, to the condition of having them will not work; each mutation along the way has to be adaptive, or appropriately connected with something adaptive. (2) There does not appear to be any decent naturalistic account of the origin of life, or of language.

(K) The Argument from the confluence of proper function and reliability
We ordinarily think that when our faculties are functioning properly in the right sort of environment, they are reliable. Theism, with the idea that God has created us in his image and in such a way that we can acquire truth over a wide range of topics and subjects, provides an easy, natural explanation of that fact. The only real competitor here is nontheistic evolutionism; but nontheistic evolution would at best explain our faculties' being reliable with respect to propositions which are such that having a true belief with respect to them has survival value. That does not obviously include moral beliefs, beliefs of the kind involved in completeness proofs for axiomatizations of various first order systems, and the like. (More poignantly, beliefs of the sort involved in science, or in thinking evolution is a plausible explanation of the flora a fauna we see.) Still further, true beliefs as such don't have much by way of survival value; they have to be linked with the right kind of dispositions to behavior. What evolution requires is that our behavior have survival value, not necessarily that our beliefs be true. (Sufficient that we be programmed to act in adaptive ways.) But there are many ways in which our behavior could be adaptive, even if our beliefs were for the most part false. Our whole belief structure might (a) be a sort of byproduct or epiphenomenon, having no real connection with truth, and no real connection with our action. Or (b) our beliefs might be connected in a regular way with our actions, and with our environment, but not in such as way that the beliefs would be for the most part true.

Can we define a notion of natural plausibility, so that we can say with Salmon that belief in God is just implausible, and hence needs a powerful argument from what is plausible? This would make a good section in the book. Here could argue that what you take to be naturally plausible depends upon whether you are a theist or not. (It doesn't have to do only with what seems plausible to you, or course) And here could put into this volume some of the stuff from the other one about these questions not being metaphysically or theologically neutral.

Patricia Churchland (JP LXXXIV Oct 87) argues that the most important thing about the human brain is that it has evolved; hence (548) its principle function is to enable the organism to move appropriately. "Boiled down to essentials, a nervous system enables the organism to succeed in the four F's: feeding fleeing, fighting and reproducing. The principle chore of nervous systems is to get the body parts where they should be in order that the organism may survive. . . . . . Truth, whatever that is, definitely takes the hindmost." (Self-referential problems loom here.) She also makes the point that we can't expect perfect engineering from evolution; it can't go back to redesign the basics.

Note that there is an interesting piece by Paul Horwich "Three Forms of Realism", Synthese, 51, (1982) 181-201 where he argues that the very notion of mind independent truth implies that our claims to knowledge cannot be rationally justified. The difficulty "concerns the adequacy of the canons of justification implicit in scientific and ordinary linguistic practice--what reason is there to suppose that they guide us towards the truth? This question, given metaphysical realism, is substantial, and, I think, impossible to answer; and it is this gulf between truth and our ways of attempting to recognize it which constitutes the respect in which the facts are autonomous. Thus metaphysical realism involves to an unacceptable, indeed fatal, degree the autonomy of fact: there is from that perspective no reason to suppose that scientific practice provides even the slightest clue to what is true. 185 ff.

(L) The Argument from Simplicity
According to Swinburne, simplicity is a prime determinant of intrinsic probability. That seems to me doubtful, mainly because there is probably no such thing in general as intrinsic (logical) probability. Still we certainly do favor simplicity; and we are inclined to think that simple explanations and hypotheses are more likely to be true than complicated epicyclic ones. So suppose you think that simplicity is a mark of truth (for hypotheses). If theism is true, then some reason to think the more simple has a better chance of being true than the less simple; for God has created both us and our theoretical preferences and the world; and it is reasonable to think that he would adapt the one to the other. (If he himself favored anti-simplicity, then no doubt he would have created us in such a way that we would too.) If theism is not true, however, there would seem to be no reason to think that the simple is more likely to be true than the complex.

(M) The Argument from induction
Hume pointed out that human beings are inclined to accept inductive forms of reasoning and thus to take it for granted, in a way, that the future will relevantly resemble the past. (This may have been known even before Hume.) As Hume also pointed out, however, it is hard to think of a good (noncircular) reason for believing that indeed the future will be relevantly like the past. Theism, however, provides a reason: God has created us and our noetic capacities and has created the world; he has also created the former in such a way as to be adapted to the latter. It is likely, then, that he has created the world in such a way that in fact the future will indeed resemble the past in the relevant way). (And thus perhaps we do indeed have a priori knowledge of contingent truth: perhaps we know a priori that the future will resemble the past.) (Note here the piece by Aron Edidin: "Language Learning and A Priori Knowledge), APQ October l986 (Vol. 23/ 4); Aron argues that in any case of language learning a priori knowledge is involved.)

This argument and the last argument could be thought of as exploiting the fact that according to theism God has created us in such a way as to be at home in the world (Wolterstorff.)

(N) The Putnamian Argument (the Argument from the Rejection of Global Skepticism)
Hilary Putnam (Reason Truth and History) and others argue that if metaphysical realism is true (if "the world consists of a fixed totality of mind independent objects", or if "there is one true and complete description of the 'the way the world is'") then various intractable skeptical problems arise. For example, on that account we do not know that we are not brains in a vat. But clearly we do know that we are not brains in a vat; hence metaphysical realism is not true. But of course the argument overlooks the theistic claim that we could perfectly well know that we are not brains in a vat even if metaphysical realism is true: we can know that God would not deceive us in such a disgustingly wholesale manner. So you might be inclined to accept (1) the Putnamian proposition that we do know that we are not brains in a vat (2) the anti-Putnamian claim that metaphysical realism is true and antirealism a mere Kantian galimatias, and (3) the quasi-Putnamian proposition that if metaphysical realism is true and there is no such person God who has created us and our world, adapting the former to the latter, then we would not know that we are not brains in a vat; if so, then you have a theistic argument.

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