In this paper, I discuss the case study of the concept ‘synapse’, focusing on a debate that took place during the mid- to late- 20th century. The ‘war of the soups and sparks’, in which scientists attempted to determine whether synaptic transmission is electrical or chemical, had just ended. The resolution of the battle over facts, however, cleared the way for a new battle – one that was fought over concepts. Specifically, scientists disagreed about the extension of the concept ‘synapse’: while some argued that the term should apply exclusively to chemical junctions, others maintained that it should extend to electrical junctions, as well.
I analyze the work of neuroscientists from both sides of the debate, most prominently Harry Grundfest and Michael Bennett. I show that what was at stake, for them, was not merely terminology. Rather, each of these alternative conceptualizations was intertwined with the production of a narrative explanation. First, each taxonomy brought to the foreground distinct similarities and dissimilarities, highlighting specific ‘why’ or ‘how’ puzzles that arose from these relations. Each taxonomy, therefore, reflected not only the integration of known facts about the objects of investigation, but the scientist’s views about the most pressing and interesting questions to be asked. Second, these taxonomic juxtapositions illustrated a preliminary roadmap for solving such puzzles through empirical research. Thus, the alternative conceptualizations of ‘synapse’ each build upon – and, in turn, contribute to – the production of narrative explanations.
