Biology and Philosophy (2007) 22:193–215 Ó Springer 2006 DOI 10.1007/s10539-006-9027-9 Occam’s Razor in science: a case study from biogeography A. BAKER Department of Philosophy, Swarthmore College, 500 College Avenue, Swarthmore, 19081, USA (e-mail:
[email protected]) Received 22 June 2004; accepted 16 March 2006 Introduction There is a widespread philosophical presumption – deep-rooted and often unarticulated – that a theory whose ontology exceeds that of its competitors is at a prima facie disadvantage. This presumption that ontologically more parsi- monious theories are preferable appears in many guises. Often it remains im- plicit. Sometimes it is invoked as a primitive, self-evident proposition that cannot be further justified or elaborated upon (for example at the beginning of Good- man and Quine’s 1947 paper,1 and in Quine’s remarks about his taste for ‘‘clear skies’’ and ‘‘desert landscapes’’). Other times it is elevated to the status of a ‘‘Principle’’ and labeled as such (for example, the ‘‘Principle of Parsimony’’). However, perhaps it is best known by the name ‘‘Occam’s (or Ockham’s) Razor.’’ The question I wish to address in this paper is whether Occam’s Razor is a methodological principle of science. In addition to being a significant issue in its own right, I am also interested in potential connections between attitudes towards parsimony in science and in philosophy. Metaphysicians might once have aimed to justify the use of Occam’s Razor in science by appeal to aprioriphilosophical principles. The rise of scientific naturalism in the second half of the 20th Century has undercut this style of approach.