Atheism and Theism JJ Haldane - Common Sense Atheism

Atheism and Theism 89
seems natural to say that these parts and functions exist for the well-being of
the animals, be they individuals or species, and, assuming that they are not
intelligent entities prudently directing their own behaviour, that the existence
of such well-organized structures points to a benign designer.
This, in essence, is the last of Aquinas’s famous five ways (quinque viae) or
proofs set out in response to the second question ‘whether there is a God’ of
the Summa Theologiae (Ia, q. 2, a. 3.). The text is brief and worth quoting in
full to give a flavour of the directness of Aquinas’s style:
The fifth way is based on the guidedness of nature. Goal-directed behaviour
is observed in all bodies in nature, even those lacking awareness; for we see
their behaviour hardly ever varying and practically always turning out well,
which shows they truly tend to goals and do not merely hit them by accident.
But nothing lacking awareness can tend to a goal except it be directed by
someone with awareness and understanding; arrows by archers, for example. So
everything in nature is directed to its goal by someone with understanding and
this we call God. 8
St Thomas’s formulation can be applied to the issue of fine tuning but at
this stage I am concerned with apparent purpose in the organization and
activity of living things. Belief in real teleology and in the need of a purposeful
agent to create and sustain it has been held to be refuted on the basis
of the theory of natural selection. Given replication, inheritance, variation,
environment and time the range of animate species is explicable in physicomechanical
terms. So it is said, but the issue is not quite so clear.
First, a concession to the anti-teleologist or mechanist. It is right for him
or her to argue that the traditional design argument is challenged by the mere
possibility of evolutionary explanations. If the existence of such complex
animals could be the result of natural mechanico-evolutionary processes, then
any argument to the effect that they could only have come into existence
through a special creation is thereby refuted. This is correct, but note where
the concession leaves the debate. Unless the evolutionist has an argument
to show that creation is excluded we are faced with competing hypotheses.
Indeed the dialectic is subtler still, since the theist may not want to exclude
evolutionary theory as an account of the history of species development but
only to reject it as a complete explanation. However, even this position requires
that he or she produce reasons for thinking that natural selection cannot be
the whole story.
I think there are three places, or points of transition, at which such reasons
may be found. First, the step from non-living to living entities; second, the
step from basic ‘life forms’ to reproductive species; and third, the transition from
mindless to minded life. I shall deal with the last of these later and at some
length but take the first and second together now.