122 J.J. Haldane
of existential and causal dependency. In one way and another St Thomas is
saying: ‘no God, no world; world, therefore God’. Against this stand two
familiar forms of objection: first, that the arguments fail; second, that even if
they worked they would not establish the existence of God. I will return to the
latter issue in the next section. Here I consider the former which itself has
two main components: first, the claim that there is nothing incoherent in an
infinite series of causes; second, the contention that in any case the idea that
things (events, objects or whatever) always require explanation rests on a false
assumption,viz. the principle of sufficient reason (PSR).
Returning to the progress review scheme and the visual depiction of it,
I chose a circular seating arrangement at an initial review to high-light the
problem. Suppose, however, that I had arranged the figures in a line receding
into the distance, each awaiting review by his predecessor. That would have
diminished the effect but would it have diminished the problem? Clearly not
if the line were finite, since if the member nearest had been reviewed then
given the rubric there would have to be a first reviewer (however that had
been effected). Assume, though, that the review scheme was already in exist-
ence and had been for as long as the university has existed. St Andrews
received its Papal Seal in 1413, so on this assumption those currently review-
ing would depend in this respect on predecessors no longer existing – still,
there would have to have been a first reviewer (deemed such by Pope Benedict
XIII, say). Suppose, however, that the university has always existed (and
perhaps always will) with each reviewer having been reviewed by a predeces-
sor and reviewing a successor ad infinitum. Given these assumptions can one
still argue that there must be a first cause of the series?
Although Aquinas believed, on the basis of scripture, that the natural
order had a temporal beginning, he argued, against St Bonaventure (1217 –
74), that reason alone could not show the impossibility of its having existed
from eternity (for ever); but that it could show the necessity of its having
been created. In other words, his arguments are intended to establish the
ontological not the temporal priority of the first cause. For all that they
are concerned, therefore, the university could have existed for ever. Still,
I suggest we should feel unhappy about the idea that there could be an
infinite causal series – for unless there was a reviewer who had not been
reviewed – an originating source of the causal power to review – how could
the series exist?
The issue is not dealt with by adverting to mathematical infinities. Suppose
we draw a section of the number line and just identify some point as −1, then
there is a prior point −2, and its predecessor −3, and so on. That is not in
dispute; what is contested is that any such infinite series could be one of
intrinsiccausal dependence. Here we need to distinguish between a series
of items the members of which are, merely as it happens, casually related to