It is widely
acknowledged that a central aim of the scientific enterprise -
whether it concerns physics, biology, or social science - is to
achieve understanding of the observed phenomena (in addition to
accurate description and prediction). But what precisely is
scientific understanding? When is it achieved? Many philosophers of
science have tried to answer these questions, but this has not led
to consensus. Presently, at least with respect to the natural
sciences, two competing positions dominate the debate: the view
that ‘causal mechanisms’ are essential to scientific
understanding, and the view that unification of the discoveries in
a social context is essential. Moreover, not only philosophers of
science but also scientists themselves disagree about standards of
understanding.
Scientific
understanding is both exciting and necessary; human cultures are
vulnerable systems whose survival is threatened, in the face of
which threat we seek moral values embedded within our scientific
knowledge. This proceeds through the interweaving of the scientific
quest with the search for moral resources that will help us
confront threats to human survival. However, we have yet to
go in integrating knowledge and values
In the 1940s and 50s
a confident, optimistic vision of science was widely shared by
philosophers and historians of science. The goal of science was to
discover the truth about nature, and over the centuries science had
advanced steadily towards that goal; science discerned the real
kinds of things of which the world was composed and the causal
relations between them; the methods of science were rational and
its deliverances objective; and so on. Only where science failed in
some of these respects was there any need to provide external, that
is social, political, or individual, explanations to bolster
scientific belief.
In the late 50s, and
especially subsequent to Kuhn's classic, The Structure of
Scientific Revolutions, all this started to change.
Historians increasingly insisted that the development of science
must be treated just like any other cultural process, which meant
embedding the narrative of the growth of scientific knowledge fully
in the social and political context in which it occurred. This
suggested that the view of science as deriving from a uniquely
rational process could no longer be sustained. And, notoriously,
Kuhn argued that science could not be seen as cumulative across the
most dramatic changes in scientific theory.
Though philosophers
have never given up entirely on the old optimistic picture of
scientific understanding ("Legend" as Kitcher refers to it), its
influence has steadily waned. For various reasons philosophers have
become increasingly concerned over whether one could believe
scientific claims to be literally true. Influenced by ideas that
scientific theory must always be underdetermined by empirical
evidence, they became more sympathetic to the possibility that
scientific belief must be explained, at least in substantial part,
by much more than the rational objective processes envisioned by
Legend.
These philosophical
doubts existed in uneasy tension with more extreme tendencies
toward thoroughgoing relativism or scepticism, and with the
movement in the sociology of science to see the whole concern with
truth. Falsity is an irrelevant diversion.
Kitcher argues that
science does indeed discover the truth about nature, that it
discerns the real kinds and their causal relations, that scientific
understanding develops progressively and cumulatively through
methods that are rational and ultimately
objective.
First, he identifies
many of the problems that arose for Legend's view of science as
resulting from a too simple conception of science. Instead of
describing scientists simply in terms of what they believed,
Kitcher introduces the holistic notion of a scientific practice,
which includes a scientist's professional language; the questions
she identifies as significant; the statements she accepts; the
patterns of explanation, or schemata, she accepts; the examples of,
and criteria for, credible informants; the paradigms of
experimentation and observation, including the instruments that she
considers reliable; and the exemplars of good and faulty scientific
reasoning .
Of particular note
is the idea of schemata for explanation, which Kitcher uses to
describe the growing explanatory resources of science. The various
developing practices of individual scientists feed into what is the
real locus of scientific progress, an advancing consensus practice.
A further major respect in which Kitcher diverges from the
classical tradition is in emphasizing that scientific practices
develop in response to encounters both with nature and with
colleagues.
If there is one
point on which substantial consensus has been reached in the
post-Legend era, it is that claims about the progressiveness of
scientific understanding need to be sensitive to the real history
of science. The most impressive aspect of Kitcher's book is the
seriousness with which he responds to this demand. The central
focus of his argument is the detailed treatment of three key
episodes in the history of science, Galileo's defence of
heliocentrism, Lavoisier's refutation of phlogiston chemistry,
and Darwin's argument for evolution by natural
selection. Most philosophers, believe that Galileo, Lavoisier
and Darwin advanced our understanding of nature, but it is not
always easy to articulate this belief. The significance of these
episodes is that they constitute advance if anything does: they are
the crown jewels of scientific history.
Kitcher argues
forcefully that Galileo, Lavoisier, and Darwin triumphed in the end
because they had the better arguments. And except for a few
scientists who were either too strongly committed to the old views
for personal or external reasons, or just plain stupid, the
scientific community eventually came to see that they had the
better arguments. The reason they had the better arguments,
moreover, was that what they claimed was true--or at least
approximately so.
