12 J.J.C. Smart
As I suggested at the beginning of this essay it is a mistake to think of
theories, even in theoretical physics, merely as useful myths. A vulgariza-
tion of Thomas Kuhn’s ideas has in some quarters led to much relativism
about truth and reality. As a corrective to this I have frequently in the past
had occasion to refer to an interesting article by Gerald Feinberg^15 in which
he claims that ‘Thales’ Problem’, the problem of explaining the properties
of ‘ordinary matter’, has been solved. The properties of the water of the sea,
the earth and rocks of the land, the light and heat of the sun, the transpar-
ency of glass, and things of that sort, can be explained definitely using only
the theory of the electron, proton, neutron, neutrino and photon and their
antiparticles if any. This theory is ordinary quantum mechanics supplemented
by the inverse square law of gravitation. (Deeper theories, such as quantum
field theory, are needed to explain the fundamental properties of the electron,
proton, neutron, neutrino and photon, requiring discussion of the more
recondite and very transient particles produced at high energies, but that
is another matter.) This part of physics, Feinberg argues, is complete. It is
not likely to be relegated to the scrap heap, as was phlogiston theory. We
must remember that even revolutions allow for approximate truth in the
proper domain of application of the earlier theories.^16 Newtonian mechanics
gives predictions that are correct within observational error for objects
whose velocities are not too high or which are not too near very massive
bodies. Sometimes indeed there can be a change in ontology. General relativ-
ity shows how to replace the notion of gravitational force in favour of the
geometrical notion of a geodesic, but much of classical mechanics has no
need of this ontology and can be stated in terms of masses and their mutual
accelerations.
With these cautions in mind, let us now look more sympathetically at
reasons why the ‘New Physics’ has suggested a more favourable attitude to
some sort of theism.
3 The New Teleology and the Old
By ‘the new teleology’ I mean the sort of teleological argument for the exist-
ence of God which rests its case on the wonders and fundamental laws of the
universe at large. Such a teleology concedes that the sort of argument used by
William Paley^17 in the nineteenth century will not do: we do not need to
postulate a designer for a kangaroo, a hawk’s eye, or the human immune
system, since the evolution of these can be explained by the neo-Darwinian
theory of natural selection together with modern genetics which includes
neo-Mendelian population genetics and contemporary ideas of molecular
biology. Molecular biology gives insight into the chemistry of how genes