Green and Shapiro's argument that rational choice theory is too inattentive to substantive matters is well taken. However, their suggestions for future research are unlikely to generate what they seek: an empirically relevant, coherent theory of political processes and a rational choice paradigm that accommodates other perspectives. To achieve this end, we require a clearer understanding of the practical objectives of our discipline and of the difference between modelling and theorizing about politics, and between science and engineering. Until the ?engineering? (...) component of the discipline assumes a more central role, research?whether theoretical, empirical, or any combination of the two?will continue to generate an incoherent accumulation of theorems, lemmas, correlations, and ?facts.? (shrink)