The logic of economic inquiry requires two distinct research programs. One program treats economic life in terms of invariant formal categories across time and place. The other program treats the continual generation of novelty and turbulence through time and human interaction. These programs are not commensurable: one cannot be reduced to the other. The former program must be conveyed by a theory of equilibrium; the latter program requires a process-based theory of emergent phenomena. Roy Weintraub articulated a neo-Walrasian research program in his General Equilibrium Analysis, and here I sketch a complementary neo-Mengerian program. In presenting this sketch, I also explain that needless analytical confusion and antagonism can result from a failure to recognize that economic analysis requires two distinct research programs. As a historical side-bar, Carl Menger probably recognized this situation, as evidenced by his correspondence with Léon Walras.