These volumes chart the fundamental - methodological and analytical - change in economics that arose in the second half of the nineteenth century. The main characteristics of this change included an increasing reliance on mathematical methods, a revolution in the theory of value, and the rise of general equilibrium theory. This collection traces this long revolution over a fifty-year period for the first time, from William Stanley Jevons' The Theory of Political Economy (1871), to Eugen Slutsky's On the Theory of the Budget of the Consumer (1915).