all natural causality as response to stimulus, and then had to postulate a stimulus which stimulated without being stimulated, and this was God.  Apart from this supreme and first stimulus nothing would in fact be moving.  The Aristotelians claimed simply to be analysing the nature of physical motion as they perceived it, and to find the necessity of perpetually applied divine stimulation implicit in it.  No violence was thereby done to the system of physical motion nor was anything brought in from without to patch it up; it was simply found to be of its own [28] nature God-dependent.

It seems as though the reproachful description ’Deus ex machina’ should be reserved for more arbitrary expedients than Aristotle’s or Leibniz’s, say for the occasionalist theory.  Occasionalism appeared to introduce God that he might make physical matter do what it had no natural tendency to do, viz. to obey the volitions of finite mind.  Ideas, on the other hand, have a natural tendency to represent one another, for to be an idea is to be a representation; God is not introduced by Leibniz to make them correspond, he is introduced to work a system in which they shall correspond.  This may not be Deus-ex-machina philosophy, but it is physical theology; that is to say, it treats divine action as one factor among the factors which together constitute the working of the natural system.  And this appears to be perhaps unscientific, certainly blasphemous:  God’s action cannot be a factor among factors; the Creator works through and in all creaturely action equally; we can never say ’This is the creature, and that is God’ of distinguishable causalities in the natural world.  The creature is, in its creaturely action, self-sufficient:  but because a creature, insufficient to itself throughout, and sustained by its Creator both in existence and in action.

The only acceptable argument for theism is that which corresponds to the religious consciousness, and builds upon the insufficiency of finite existence throughout, because it is finite.  All arguments to God’s existence from a particular gap in our account of the world of finites are to be rejected.  They do not indicate God, they indicate the failure of our power to analyse the world-order.  When Leibniz discovered that his system of mutual representations needed to be pre-established, he ought to have seen that he had come up a cul-de-sac and backed out; he ought not to have said, ‘With the help of God I will leap over the wall.’

If we condemn Leibniz for writing physical theology, we condemn not him but his age.  No contemporary practice was any better, and much of it a good deal worse, as Leibniz liked somewhat complacently to point out.  And because he comes to theology through physical theology, that does not mean that all his theology was physical theology and as such to be written off.  On the contrary, Leibniz is led to wrestle with many problems which beset any philosophical theism of the Christian type.  This is particularly so[29] in the Theodicy, as its many citations of theologians suggest.  His discussions never lack ingenuity, and the system of creation and providence in which they result has much of that luminous serenity which colours the best works of the Age of Reason.