Narratives of contingency as historical evidence for philosophical arguments of contingency: pathway decisions in the early development of molecular genetics.

This article argues that philosophical arguments of contingency in the development of science can be advanced by starting from historical evidence produced through the framework of narratives of contingency. Narratives of contingency are conceptualized both as prospective narratives constructed by historical actors to navigate decisions at what they perceived as fork moments in the present and as an analytical framework for systematically reconstructing such decision-making processes from historical sources.The argument is developed in three steps. First, the article outlines three constraints that historical case studies must explicitly address in order to function as evidence for philosophical arguments of contingency and alternative pathway possibility. These are the identification of a juncture moment in a situated trajectory, an explanatory factor linking actors' decisions to the initiation of path-dependent sequences, and an explicit specification of analytical level and scale. Second, narratives of contingency are introduced as a historical framework that enables the systematic description and explanation of pathway decision-making processes, particularly in contexts of institutional deliberation where alternative courses of action were explicitly articulated. Third, the framework is illustrated through a case study of institutional decision-making in the early development of molecular genetics in Germany (1958-1960).