Precursorism, called in its more extreme forms precursoritis or precursitis, is a characteristic of that kind of historical writing in which the author seeks antecedents of present-day institutions or ideas in earlier historical periods. This kind of anachronism is considered to be a form of Whig history and is a special problem among historians of science. The French historian of medieval science, Pierre Duhem, exemplifies several of the characteristics of the quest for precursors of modern scientific ideas. Duhem was trained as a physicist, rather than as a historian; he was French and many of the precursors he identified were French or studied at the University of Paris; he was a devout Catholic and many of the precursors of the theologically troubling Italian, Galileo, were members of religious orders. Most striking among them was the French bishop and scholastic philosopher, Nicole Oresme.
The concept has been applied to those who would find precursors of Darwin in the early Nineteenth Century, and to those who would find anticipations of modern science in ancient cultures from the Near East to Mesoamerica. Precursorism has recently been identified as a significant factor in some studies of the work of Islamic scientists.
It is now commonly assumed that historians of science should study past scientific "ideas in their own right, avoiding anachronism and precursoritis."
- "No field of historical study seems so to dispose its adherents to find anachronistic forerunners and adumbrations as does the history of science." Marshall Clagett, Nicole Oresme and the Medieval Geometry of Qualities and Motions, (Madison: Univ. of Wisconsin Pr., 1968), p. 3
- Dana B. Durand, "Nicole Oresme and the Mediaeval Origins of Modern Science", Speculum, 16 (1941): 167-185.
- "I do not wish to make overly much of this point, as "precursoritis" is the bane of historiography." Stephen Jay Gould, The Structure of Evolutionary Theory, (Cambridge: Harvard Univ. Pr., 2002), p. 138.
- "[T]he author's Whiggism leads him to see non-Western cultures, not in their own terms, but as "mirroring," "presaging," "hinting at," "bearing out," "paving the way for," "evidencing nascent understandings of," and "being the forerunner of" today's science. This malady is sometimes diagnosed as "precursoritis," and every graduate student knows that identifying who got what right or wrong by our lights is not the way–certainly not the best way–to tell the story of what people have thought about nature in other historical contexts or of how we came to know what we now know." James E. McClellan III, "Ancient Roots Forced into Modern Pots," Review of Dick Teresi, Lost Discoveries: The Ancient Roots of Modern Science: From the Babylonians to the Maya, Science, 298, (2002): 1895-1896.
- "Precursorism (which has a notorious tendency to degenerate into a disease known as 'precursitis') is equally familiar; it reads the future into the past, with a sense of elation." A. I. Sabra, "The Appropriation and Subsequent Naturalization of Greek Science in Medieval Islam: A Preliminary Statement," History of Science, 25(1987): 223-243.
- "Rationale" for International Workshop on History of Mathematics in the Last 25 Years: New Departures, New Questions, New Ideas.