Femmes finales: natural selection, physiology, and the return of the repressed

Nineteenth-century final causes were ‘barren virgins’, an aphorism attributed to Francis Bacon, but twentieth-century teleology was a ‘mistress’, an adage of uncertain provenance. A study of historical uses of these gendered metaphors is used to probe changing attitudes toward teleological reasoning in biology. At the beginning of the nineteenth-century, invocations of final causes were commonplace but such idioms are rarely used at its end. This change is commonly attributed to publication of the _Origin of Species_ in 1859 which completed the ejection of final causes from biology. Charles Darwin, however, openly and unashamedly uses teleological reasoning and language in his botanical research. He believed he had naturalized, rather than eliminated, the concept of final cause. A more important reason for the eclipse of final causes was the shift within physiology toward the explanatory modes of the physical sciences which had long held final causes in disrepute. The rejection of final causes as explanatory principles occurred despite a persistence of teleological reasoning that was experienced as a ‘guilty secret’ likened to a mistress that a physiologist could not give up but would not acknowledge in public. Biology’s ambivalent attitude toward teleological explanations persists in the twenty-first century.