Theory and Evidence

Mark Irving Lichbach

In their debate on neopositivism, while Kratocwil danced with relativism, Pollins stressed the value of positivism to qualitative researchers, and Hopf recognized the importance of making interpretations more rigorous. Listening to their stimulating debate, Chernoff tried to clarify the nature of naturalism, and Waldner probed the idea of causal mechanisms.

Trying to understand the implications of the debate for social science practice, Lawrence subjected the empirical claims of the democratic peace literature, and Levy international relations research programs more broadly, to scrutiny. Bernstein, Lebow, Stein, and Weber summarize and extend these analysesby making a plea for case-based reasoning. We need to understandthese debates in terms of three principles of the traditional positivist philosophy of science.

1. Theory is deductive-nomological: it begins as abstract, axiomatic, and foundational; it becomes subsuming, integrating, and unifying; and it ends as organized, comprehensive, and encyclopedic.
2. Evidence is oriented toward falsification: scientists attempt to reject a hypothesis; after one possible explanan is discarded, they investigate another to see if it can account for the explanandum.
3. Evaluation is therefore based on deductive and nomological laws that resist falsification: these laws establish the ever-expanding domain of a theory; science therefore succeeds when it discovers universal laws that are true.

This philosophy of science might have suited social scientists a few decades ago. Today’s more modest philosophy of science that consists instead of three different principles.

1. Theory consists of research programs that contain nuts and bolts; these causal mechanisms are combined into models of a theory that suggest lawful regularities.
2. Evidence establishes the applicability of these models of a theory for the models of data that exist in particular domains; the elaboration of a theory thus delimits the theory’s scope.
3. Evaluation grapples with the problem that the science that results from following the first two principles is prone to nonfalsifiability and to self-serving confirmations. Confrontations between theory and evidence are thus evaluated in the context of larger structures of knowledge.

This final chapter moves the debate (Lichbach 2004) forward by dealing with the problem of evaluation. For pragmatists who work with a thin version of one paradigm, Lakatos’s (1970) “additional and true” standard, which lets them explore rationalist, culturalist, and structuralist approaches on their own terms, is applied. For competitors who employ alternative paradigms, Popper’s (1968) “different and better” standard, which lets them conduct competitive evaluations among alternative rationalist, culturalist, and structuralist explanations, is employed. And for hegemons who synthesize the different paradigms into one thick paradigm,“ nested models” that combine the two standards, and thus lets them compare syntheses to their components (models and foils), is used.

Source: Theory and Evidence in Comparative Politics and International Relations Edited by Richard Ned Lebow and Mark Irving Lichbach, 2007.