The biographical study of scientists, though familiar, has mostly seemed anodyne rather than profound as a tool of history of science. But it bears closely on the public role of the scientist, associated nowadays with the detachment of objectivity and with a sense of the scientific life as a fracturing of “the science” from other aspects of a career. Although this division is indeed characteristic of the modern scientific identity, historians should not take it as natural or inevitable. The life (...) of the statistician Karl Pearson, who endeavored to live out a Bildungsroman, demonstrates the survival into the twentieth century of alternative ideals and, with them, of ambitions for science going far beyond the professionalization of a technical field. Pearson’s career offers a model for historicizing the relationship of science to public reason. (shrink)