ARGUMENTS FOR MONOTHEISM 19311 T has already occurred.
12 If T has already occurred, then nothing exists now. So:
13 Nothing exists now (from 10 through 12).
14 If for all X, X’s non-existence is possible, then nothing exists now (from 4
through 12).
15 It is false that nothing exists now. So:
16 It is false that for all X, X’s non-existence is possible.
17 If it is false that for all X, X’s non-existence is possible, then something
exists whose non-existence is impossible. So:
18 Something exists whose non-existence is impossible (from 16 and 17).
Aquinas’s Third Way is read in different ways. Aquinas is read as saying either:
(a) It is impossible that all generable things exist at every single time. ( =
Necessarily, every generable thing at some time or other does not exist.)
or:
(b) It is impossible that, at every time whatever, some generable thing exists.
(Necessarily, at some time or other, no generable thing exists.)
Compare Necessarily, every elk passes on sooner or later; this is analogous to
(a). Consider Necessarily, at some time, there are no elk at all; this is
analogous to (b). What Aquinas needs is (b); (a) will not help him. Aquinas also
needs:
(c) It is impossible that everything that exists is a generable being.
This indication of what he requires is relevant to two fallacious inferences
he is often charged with making in the Third Way; either would, of course,
invalidate the argument.
Inference one: from A to B
Consider:
A For all X, it is possible that X corrupt.
B It is possible that everything (simultaneously) corrupt.
A world W of which A is true might be one of which it was also true that:
C It is not possible that W be entirely unpopulated.