Resolving a Controversy: The Non-Classical Ion Debate

Abstract

This paper examines a scientific controversy that raged for twenty years in physical organic chemistry during the second half of the twentieth century. After explaining what was at stake in the Non-Classical Ion Debate, I attempt—by examining the methodological reflections of some of the participants—a partial explanation of why this debate was so difficult to resolve. Instead of suggesting a breakdown of scientific method or the futility of appeals to evidence, the endurance of this controversy instead reveals the heuristic character of many of the explanations and predictions generated by theoretical organic chemistry. The results in this case are used to suggest a new role for the study of scientific controversies in revealing the economics of inquiry in scientific fields.