“A good man cannot teach zoology”: chemicalization, molecularism, and the transformation of biology’s self-image

This paper traces the transformation of biology’s self-image through the concept of molecularism: the cultural myth that crystallised around the success of molecular biology in the twentieth century. Beginning with Theodosius Dobzhansky’s 1964 observation that “a good man cannot teach zoology” — a symptom of the internal devaluation of an entire epistemic tradition — the paper argues that molecular biology did not merely adopt chemical methods but internalised chemistry’s constitutive agenda: a purposive orientation in which understanding a material system is inseparable from the capacity to transform it. This chemical agenda, rooted historically in the Rockefeller Foundation’s deliberate investment in the molecular approach and philosophically in the productive, synthesis-oriented dimension of chemistry identified by Bensaude-Vincent and Simon, crystallised over the second half of the twentieth century into a cultural myth in Mary Midgley’s sense — a structuring imaginative framework operative in scientific self-understanding, popular culture, policy, and commercial practice. The paper examines how popular culture stabilises and amplifies molecularism, how it re-enters scientific practice through AI-driven biology, synthetic biology, and the eugenic applications of genomics, and how it has reshaped biology’s institutional architecture through the fusion of biology with medicine. The paper argues that biology has developed a cultural unconscious — assumptions about what it is and what it should be doing that operate below the level of explicit methodological reflection. Recognising molecularism as a historically contingent framework rather than scientific necessity is proposed as a precondition for both a revised biological self-image and an ethics of molecular biology adequate to its subject matter.