"I have conceived of a society," writes Barnes, "as a distribution of selfreferring knowledge substantially confirmed by the practice it sustains" (1988, p. 166). The Black-Scholes-Merton model informed practices such as spreading, and those practices in their turn helped to create patterns of prices of which the model was a good empirical description. In that sense, the performativity of the model was indeed Barnesian.

Donald MacKenzie, An Engine, Not a Camera, loc. 148