Biologists search for the conditions that make living things amenable to human understanding, as well as the conditions that make life itself possible, and philosophers study the rational procedures of the biologists. I am interested in the way that biologists combine different kinds of discourse within a single research program. In (botanical) population genetics, for example, they combine records of populations cultivated in the field with the abstract methods of mathematical statistics, and so must develop strategies of combination, because science is constrained by the need for successful reference as well as for abstract, integrative, analytic theorizing: in general these demands require disparate modes of representation.
During the past few decades, philosophers of biology have debated the issue of reductionism versus anti-reductionism, with both sides often claiming to champion a 'pluralist' position. However, in this debate both sides tended to focus on a single research paradigm, which analyzes living things in terms of certain macromolecular components. In his influential essay, "Reductionism in an Historical Science," Alex Rosenberg reviews debates about philosophical reductionism in relation to biology over the past few decades. He observes correctly that the original terms of the debate have been radically altered, for the model of inter-theoretical reduction offered by Ernest Nagel in 1961 required the laws of the reduced theory to be deduced as theorems from the axioms of the reducing theory. The reduced theory is thus eliminated, re-written into and subsumed by the reducing theory. Because valid deduction requires that the language in which both theories are expressed be homogeneous, a set of ‘bridge principles,' a kind of isomorphism between the items of both theories, is needed to secure the re-writing. This model proved unworkable for the reduction of biology to molecular biology (thence to chemistry and physics), both because biology does not have a corresponding axiomatization, and because there is no one-to-one structure preserving correspondence between biological items (even the fundamental ‘gene') and those of molecular biology.
Rosenberg however defends a more refined reductionism, which abandons the ideal of eliminativism, as well as the deductive-nomological model of explanation. Biology, Rosenberg concedes, offers historical explanations about local patterns that are well enough defined to make prediction possible but ungoverned by any universal and necessary laws except for the principle of natural selection; and these explanations will retain some of the vocabulary of ordinary biology (gene, phenotype, cell, organism, etc.) in so far as they explain how some item or process is possible. The revised reductionist claim is then that all such explanations must ultimately include molecular explanations; that is, any biological explanation will be incomplete and so not truly explanatory, until it has been completed by the macro-molecular genetic and biochemical pathways that are causally necessary to the truth of the purely functional ultimate explanation.
Rosenberg summarizes his position in terms of a methodological dictum aimed as much towards biologists as philosophers: molecular biology must always deepen and complete other kinds of explanation in biology, in order to make explanations complete, adequate, correct, and predictive. So it seems as if a biologist might hesitate to publish a paper that does not include a section on molecular biology as its ‘last word,'or to devise new methods that don't involve carrying biological material back to the lab for chemical analysis. One way to counter the kind of ‘pluralist' reductivism that Rosenberg espouses, then, is to find important biological research that investigates organisms and populations, and contains no talk of molecular biology. Such a case study will be all the more persuasive if the research also introduces an innovative method that allows for more reliable prediction and sheds new light on the meaning of the principle of natural selection itself. Thus I have presented a case study where biologists pursue other analytic pathways, in a tradition of quantitative genetics that originates with the initially purely mathematical theories of R. A. Fisher, J. B. S. Haldane, and Sewall Wright in the 1930s. Aster Models (developed by Ruth Shaw and Charles Geyer) offers a class of statistical models designed for studying the fitness of plant and animal populations, by integrating the measurements of separate, sequential, non-normally distributed fitness components in novel ways. Their work generates important theoretical and practical results that do not require elaboration by molecular biology, and thus serves as a counterexample to the claims of philosophers whose ‘pluralism' still harbors reductionist assumptions.
This research is more of a project and promise than my work on space, time and cosmology as a case study in philosophy of physics, or my work on number theory as a case study in philosophy of mathematics. However, it ties in with material that I have repeatedly taught in my philosophy of science courses, as well as themes in 17th - 19th century European philosophy concerning the life sciences that interest me; some of my graduate students and post docs have worked in this area. It also bears on issues in environmental ethics and the prudential aspects of modern science. I am also planning to use the work and methods of my brother, Ted Grosholz, a marine biologist at the University of California / Davis, as a second case study. His research, in addition to being methodologically interesting for a philosopher, has significant consequences for the continuing health of our environment (in particular, the Pacific littoral in North and South America and more specifically San Francisco Bay), as does that of Shaw and Geyer (who study the remnants of the great Midwestern prairies).
This research has resulted in the following publications:
And I have given the following presentations on these topics: