Gilbert and Mulkay, in their paper ‘Experiments Are the Key’, present responses of scientists to questions about the development of the chemiosmotic hypothesis of energy coupling in oxidative and photophosphorylation, and infer from these responses both the meaninglessness of the concept ‘key experiment’ and the hopelessness of searching for any data as a bedrock for historical analysis. Gilbert and Mulkay's nihilism is, however, rooted in a lack of understanding of the specific scientific issues involved. A closer look at a proposed ‘key experiment’ shows certain obvious characteristics that could be criteria for a ‘key experiment’ moreover, the actual scientific response to that experiment demonstrates its pivotal role in the development of the field. Instead of demonstrating the lack of empirical bases for scientific judgment, Gilbert and Mulkay demonstrate the necessity for identifying the crucial issues and pursuing them, in questioning the scientists as well as in examining other sources.