Cosmological arguments for God’s existence

     St. Thomas Aquinas’ first three ‘ways’ of proving the existence of God all inquire into origins--they ask, crudely, how it all got started or where it all came from.  Change, motion, and the existence of ordinary things all depend on previous change, motion, or the existence of earlier things.  Aquinas argued that this chain of dependence could not stretch indefinitely backward; it could not go to infinity, or the process never could have gotten started at all.  Thus there must be First Cause and Unmoved Mover, ‘and this everyone understands to be God.’

     Those arguments are controversial, and in particular commentators have wanted to know why the chain of dependency couldn't ‘go to infinity.’  Samuel Clarke therefore produced a version of the cosmological argument that does not assume ‘the supposed impossibility of infinite succession.’  Here is my own reconstruction of Clarke's argument:

           1.  Nothing is produced out of nothing.

           2.  If there had ever been a time at which nothing at all existed, then nothing would exist now.   [1]

   But   3.  Something exists now.

    So   4.  There has never been a time at which nothing at all existed.   [2,3]

    So   5.  The universe (= the material world plus whatever else there may be) has existed ‘from eternity.’   [4]

           6.  Either the universe consists of an ‘endless’ [he means beginningless] series of dependent beings, or there is in it (at least) one being
                which is independent.

           7.  If every part of a collection or series is dependent, the series as a whole is dependent.

    So   8.  If the universe consists of a beginningless series of dependent beings, then the universe itself is a dependent being.   [7]

   But   9.  The universe itself is not dependent.  [Trivial, given our technical definition of ‘universe’]

    So  10. The universe does not consist of a beginningless series of dependent beings.   [8,9]

    So  11. There is (at least) one being that is independent.   [6,10]

          12. Any being must be (a) produced from nothing or (b) produced by some antecedently existing thing or (c) ‘self-existing’
                (produced by nothing at all, existing by its very nature).

    So  13. The independent being is self-existing.   [1,9,11,12]

...and this everyone calls God, QED.  (Note that the material world itself cannot be the independent being, as Spinoza once suggested, simply because it isn’t independent, as can be shown by adapting steps 7 and 8 to the material world rather than the universe.)

     It is a long way from the conclusion that there is an “independent being” to the identification of that being with (the traditional Judeo-Christian) God, as we noted in the case of Aquinas’ first three “ways.”  But Clarke is sensitive to this and later provides further arguments for the omnipotence, omniscience, goodness etc. of the independent being.
 

Teleological arguments

     Teleological arguments infer the existence of God from features of the material world that seems to exhibit purpose, function, or design.  Paley’s argument, a generalization from his example of the watch, goes as follows:

          1.  Artifacts are characterized and identified as such in virtue of the adaptation of their various parts to an end or purpose.

          2.  It is in virtue of this adaptation that we rightly infer them to be the products of conscious, intelligent design.

   But  3.  Nature as a whole, and particularly the living animals within it, exhibit this same adaptation (and to a dramatically higher degree).

    So  4.  Nature too is the product of conscious, intelligent design.

...and this designer everyone calls God, QED.  (Here again, further work would be needed to justify this last bit, but it is a less ambitious step than Aquinas’ or Clarke’s.)

     The argument is not strictly valid.  Though of course we do infer a designer when we see a watch, that conclusion does not very strictly follow; it is still conceivable, however preposterously unlikely, that the watch fell together coincidentally, by a huge cosmic accident, as a result of freakish radiation from the sky.  And the same holds for the inference of 4 from 3.  But that’s OK.  The inference need not be taken as deductive; we can regard it as an instance of inference to the best explanation.  The watch’s adaptation of parts to purposes does not strictly entail that it was manufactured by a designer, but the designer hypothesis is by far the most reasonable explanation of the adaptation.  So too, Paley thinks, the hypothesis of an intelligent creator is far and away the most reasonable explanation of the world’s adaptation.