Considering the case of Juan de Vilanova y Piera, often celebrated as the first scientist to accept the prehistoric antiquity of palaeolithic paintings, we explore some of the problems related to the concept of ‘precursor’ in the field of the history of science. In the first section, we propose a brief history of this notion focusing on those authors who have reflected critically on the meaning of predecessors. In the second section, the example of Vilanova illustrates the ways in which historians of science have created precursors. From the vantage of modern science, precursors have traditionally been defined as those who first indicated or announced ideas or theories later accepted by the scientific community. As a result, they have been represented as ‘heroes’ struggling hard to defeat the ignorance of their time. As the case of Juan de Vilanova illustrates, this traditional view is unsatisfactory in many ways. For this reason we consider in the third section a number of methodological strategies to promote a more adequate approach to pioneers. In particular, we suggest that the best way to surmount hagiographical approaches to past scientists is to put them in their own intellectual and historical contexts.