"This is a wonderful book! In "How Scientists Explain Disease," Paul Thagard offers us a delightful essay combining science, its history, philosophy, and sociology.

Some biologists such as Ernst Mayr insist on replacing the expression teleology which they find suspect with teleonomy to only refer to goal-directed processes in the life sciences. Others like Francisco Ayala argue that the extant word teleology is preferable provided one differentiates the myriads of applications utilized in biology. When one understands the history of the term teleology it is not surprising that there are two divergent theses concerning the use of the locution in evolutionary biology. This paper offers (...) a solution of this infelicity. Although it might appear that this issue only concerns the replacement of one locution for another, much more is involved. For example, Ayala is committed to defending the autonomy and unique nature of the life sciences. I subsequently champion Ayala's thesis and argue that his approach is closer to currently successful biological practice and of greater heuristic promise for future research than is Mayr's. (shrink)

The etiological approach to ‘proper functions’ in biology can be strengthened by relating it to Robert Cummins' general treatment of function ascription. The proper functions of a biological trait are the functions it is assigned in a Cummins-style functional explanation of the fitness of ancestors. These functions figure in selective explanations of the trait. It is also argued that some recent etiological theories include inaccurate accounts of selective explanation in biology. Finally, a generalization of the notion of selective explanation allows (...) an analysis of the proper functions of human artifacts. (shrink)

Formulations of the essential commitment of the etiological theory of functions have varied significantly, with some individual authors' formulations even varying from one place to another. The logical geography of these various formulations is different from what is standardly assumed; for they are not stylistic variants of the same essential commitment, but stylistic variants of two non-equivalent versions of the etiological theory. I distinguish these “strong” and “weak” versions of the etiological theory (which differ with respect to the role of (...) selection in their definitions of function), draw out their respective implications, and argue that the weak version is to be preferred to the strong. (shrink)

Machines and Biology have been, since antiquity, closely related. From the zoological figures present in astronomical simulacra, through renaissance mechanical imitations of animals, through Decartes' wind pipe nerves, to present day discussions on the computer and the brain, runs a continuous thread. In fact, the very name of mechanism for an attitude of inquiry throughout the history of Biology reveals this at a philosophical level. More often than not, mechanism is mentioned in opposition to vitalism, as an assertion of the (...) validity of the objectivity principle in biology: there are no purposes in animal nature; its apparent purposefulness is similar to the purposefulness of machines. Yet, the fact that one picks machines as a set of objects comparable to living systems, deserves a closer look. What in machines makes it possible to establish such a connection? (shrink)