Professional science as a largely middle class occupation emerged in the nineteenth century and expanded dramatically in the twentieth. Scientists' growing administrative duties, in particular, afforded middle class status, but also worked to marginalize women and, often, ethnosectarian minorities. Scientists' technical expertise made them valuable but also troublesome to states and other patrons. Divisions within their professional communities encouraged scientists to carry their arguments into the public sphere. This “unbounding” has blurred the lines between professional science and its pretenders, but has also made science more responsive to its environment.