PHILOSOPHY OF NATURE AND PHILOSOPHY OF SCIENCE: THE CASE OF GEOLOGY
At the end of last century, Geology, under the positivist drive
of a continuous social progress, grew as a science of mapping and
exploration for mineral resources. It reflected the general deterministic
approach to the study of natural phenomena (many cases, which for a long
time were regarded as indicating a mysterious and extraordinary agency,
were finally recognized as the necessary result of the laws now governing
the material world, see Charles Lyell, Principles of Geology, 1832).
The end of this century is marked by a crisis of reason and a more pessimistic attitude towards the future and towards science and technology. Uncertainty and indetermination are recognized as essential elements of physical reality from the ultramicroscopic world of elementary particles to the macroscopic level of chaotic and complex systems (ecosphere, climate, etc.). Geology has consolidated its roots in the last century, also getting a professional status. Among practical aspects of Geology, hazards and environmental issues are becoming predominant on finding and exploiting georesources. An indicator is the urge to face the problem of Global Change, which implies the need to introduce an Earth System Science. Its aim: to obtain a scientific understanding of the entire Earth system on a global scale by describing how its component parts and their interactions have evolved, how they function, and how they may be expected to evolve on all timescales. Its challenge: To be able to predict those changes that will occur in the next decade to century, both naturally and in response to human activity (ESS-NASA, 1988). In spite of its enormous progresses, Geology has not improved its conceptual status in the last two centuries. On the contrary, its weight and visibility in the scientific community are decreased; neither has the profession obtained a high social recognition, at least in Europe. If Hutton and Newton were regarded as natural philosophers on a par in the 18th century, and Lyell, Darwin and other great students increased the prestige of Geology in the 19th, today Geology is considered by many people as a minor or ancillary science, or even a non-science, under the influence of thinkers such as Karl Popper (what is not amenable to experiment is not falsifiable; therefore, it is not science; Geology is observational but not experimental) and of a restricted notion of science, popular among physicists and philosophers of science, and according to which the book of the universe is written in mathematical language and "omnia in mensura, numero et pondere". Geology, which neglects essence for details, does not discover laws, is talkative and qualitative etc.; it is thus excluded from the mainstream of modern science. When it does not limit itself to "stamp collecting" (e.g., classifying rocks, minerals and fossils), it has at most the charm of adventure and exploration, the appeal of fantasy and magic (the geologist as Indiana Jones, more or less)
What are the reasons for this diminished status? Lack of conceptual advancement or appeal? Dependence from other sciences? (see, for ex., applications of radioactivity or magnetism do rock dating). True, Geology has not refined its intellectual tools at the same pace as physics or chemistry: the intuition of the depth of time, for example, could not allow geologists to counteract the sound arguments of Lord Kelvin about the short age of the Earth. It is also true, on the other hand, that the sound, rational arguments of Galilei were not sufficient to convince the Inquisition. Just to show that a favourable social and cultural context is needed for accepting scientific "truth", Leonardo used logical and correct reasoning to show the reality of fossils, but over a century elapsed before his arguments were accepted. He made use, too much in advance, of observation ve rsus authority of tradition, of inference versus deduction, of analogy between past and present phenomena against their separation ("revolutions" of Nature in the mysterious past, quiet in the Present"). In any case, the fact that Geology lagged behind other sciences in terms of quantification, modelization and generalization of phenomena is partly due to its inherent limits. Think of this: Geology deals with a) past events, which are not reproducible; b) individual or unique objects and phenomena; c) dynamic, mostly non linear and chaotic systems; d) complex systems observable in nature, hardly so in the laboratory. However, it has adopted all the tools that other sciences and technology have developed to investigate the world, including those of Big Science (see Marine Geology, ODP etc.). It has no laws, but leading principles: 1. the uniformitarian approach (the present is the key to the past), 2. its reciprocal, evolutionary approach (the present is the product of the past), 3. the "detective paradigm" which is shared by History (search every kind of document or evidence left...select, discard, jumble, compare, deduce and infer...; see A.Manzoni). On this base, Geology has much in common with Astronomy: the objects in the sky are fossils, too, and their light talks about past events. But Astronomy is more appealing to the layman. Maybe he has more respect or fear for the skies than for Mother Earth!
As a concluding remark, I should say that it does not make sense to
expect from Geology the precision of an "exact" science or its complete
reduction to measurements, formulae and models. It is enough, Popper may
forgive, to accept as science every intellectual activity based on reason
and aimed at understanding the world around us and within us. After that,
it is primary responsibility of geologists to believe in the tremendous
potentiality of their science, not to indulge in erecting fences
to protect their turf, and to interact with other natural scientists with
a common goal: an integrated, holistic Earth Science.