Ernst Mayr's typological/population distinction is a conceptual thread that runs throughout much of his work in systematics, evolutionary biology, and the history and philosophy of biology. Mayr himself claims that typological thinking originated in the philosophy of Plato and that population thinking was first introduced by Charles Darwin and field naturalists. A more proximate origin of the typological/population thinking, however, is found in Mayr's own work on species. This paper traces the antecedents of the typological/population distinction by detailing Mayr's changing (...) views of species between 1942 and 1955. During this period, Mayr struggles to refine the biological species concept in the face of tensions that exist between studying species locally and studying them as geographically distributed collections of variable populations. The typological/population distinction is first formulated in 1955, when Mayr generalizes from the type concept versus the population concept in taxonomy to typological versus population thinking in biology more generally. Mayr's appeal to the more general distinction between typological and population thinking coincides with the waning status of natural history and evolutionary biology that occurs in the early 1950s and the distinction plays an important role in Mayr's efforts to legitimate the natural historical sciences. (shrink)

This paper describes two collaborative projects that illustrate the value of learning symbolic logic and provide students (and instructors) a break from the routine work of learning new symbols or proof techniques. The first project has students work together to reconstruct the argument in Peter Singer’s “Famine, Affluence, and Morality”. This project has the benefit of showing students that what they are reading in college has an underlying logical structure and that their knowledge of conditionals, conjunctions, etc. functions in real, (...) argumentative discourse. The second project introduces students to four key concepts: self-reference, paradox, and metatheory, and then exposes them to key metatheoretic concepts (consistency and completeness) and to Gödel’s incompleteness proof. (shrink)