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This week, the Chair of Philosophy at the London School of Economics,
occupied from 1949 to 1969 by Karl Popper, will pass to the American philosopher,
Nancy Cartwright, from Stanford University in California. Both are leading
philosophers of science, but Cartwright’s ‘bottom up’ approach contrasts
strongly with Popper’s lofty vision.

In his 1959 preface to the Logic of Scientific Discovery, Popper wrote:
‘All science is cosmology, I believe, and for me the interest of philosophy,
no less than science, lies solely in the contribution which it has made
to it.’ The importance of experimental science then lies in weeding out
the weak theories, leaving the unrefuted (although, of course, refutable)
conjectures to struggle for supremacy. Places such as CERN, the European
Laboratory for Particle Physics, derive much of their raison d’etre from
their role as battlefields for this conflict.

The authority of science, however, seems to derive from another source.
It is the technological success and the power derived through it which have
mainly impressed politician and public alike. And Cartwright sets out to
challenge the claim that this success is in any way connected to victories
in the more esoteric intellectual competition (which is a bit galling to
those of us working in the pure sciences).

Cartwright distinguishes the high level ‘covering laws’, such as quantum
electrodynamics, from the laws governing the operation of devices, such
as lasers, that they claim to explain. It is the ‘deductive-nomological’
account which Cartwright dismisses – the idea that the explanation hinges
on deduction from the higher law.

She sees the working physicist in the ‘real world’ (as I understand
life outside CERN is called), making do with phenomenological rules (that
is, rules of thumb, rules derived from the way that phenomena present themselves)
and causal stories (describing things in terms of causes and effects) without
recourse to the covering laws. Supposed derivations of the working rules
from the covering laws are, says Cartwright, usually elaborate fabrications
to justify the existence of the covering laws which, in fact, serve only
as redundant metaphysical baggage.

Cartwright does concede that the covering laws can occasionally serve
a real purpose. For example, she accepts the point made by Ian Hacking,
professor of philosophy at the University of Toronto, that in experiments
such as a Millikan-style fractional charge search, the contortions of language
needed to avoid treating the electrons and positrons used to charge a suspended
niobium ball as real, do seem far-fetched: (‘If you can spray them then
they’re real.’) But even though she accepts that some ‘theoretical entities’,
as she would have them – such as electrons and positrons – may actually
exist, she is deeply sceptical of the grandiose theoretical constructions
that allegedly rule their behaviour.

There is, however, a cultural dimension to the scientific enterprise
which is completely neglected in Cartwright’s pioneering book How the Laws
of Physics Lie, first published in 1983. It is to this, I believe, that
the beleaguered theoretician can turn for solace. In 1981, Gerald Holton,
professor of physics at Harvard University, described what he saw as the
remarkable ambitiousness of theoretical physics. He sees this endeavour
motivated by the quest for a ‘Holy Grail’, which is no less than ‘the mastery
of the whole world of experience, by subsuming it ultimately under one unified
theoretical structure’. It is this drive, motivated no doubt by the strong
aesthetic prejudice that there must be a single neat solution, which illustrates
the important interplay between our society’s culture and its science.

This idea is strongly suggestive of the extent to which we are constrained
to model the world in our own image. For me the crucial issue here is whether
this ‘monotheorist’ ambition could ever have become so thoroughly established
without the ground being prepared by the long tradition of monotheist belief.
To argue the cultural autonomy of science is to neglect its intimate relationship
with the development of European society, a relationship where important
influences have passed in both directions.

Within the tradition of Continental philosophy, several thinkers have
observed that science is fundamentally a creative, rather than merely descriptive,
enterprise. In the writings of Friedrich Nietzsche, over a century ago,
we find the assertion: ‘The scientific man is the further development of
the artistic man.’ But as with great art, great science makes us believe
instinctively that there are important truths to be learnt only from its
study. Unfortunately, the austere medium of mathematics leads to a rather
esoteric genre which requires years of dedicated training. This is why as
much as possible needs to be done to communicate the excitement of pure
research and the beauty of the theoretical vision that motivates it. Resting
the case for pure science funding on talk of ‘spin-off’ is both irrelevant
and misleading. It is to Popper’s lofty vision rather than Cartwright’s
more practical perspective that we are obliged to turn for justification.

Phil Allport works in the High Energy Physics group at the Cavendish
Laboratory, Cambridge.