The activities of political scientists can either frustrate or contribute to human emancipation. That is the lesson of the exposé of frustration in Chapter 8 and the discussion of a potential contribution in Chapter 9. However, even if they accepted the arguments of these chapters to the extent of (say) renouncing opinion surveying, many political scientists might still claim that emancipation is of no proper concern to a discipline whose essential task is explication and explanation of the political world, not evaluation, prescription, or criticism.

In this chapter I shall argue that even if one regards explanation as the sine qua non of social science, one cannot avoid taking sides on issues of domination and liberation. Nor is the matter one of simply choosing sides as one will. For if political science is to redeem its claim as a progressive and cognitively rational explanatory discipline - and dare one say a science worthy of the name - then its practitioners simply must commit themselves to the canons of communicative rationality. My argument commences with a contemplation of what progress and cognitive rationality mean and entail when it comes to social science.

Progress consists of an increasing ability to explain and connect complex phenomena. Progress in science, as in any rational activity, implies choice between competing explanations, theories, or theoretical frameworks based on good cognitive reasons. Good cognitive reasons can take many forms: problem-solving power, predictive success, consistency, simplicity, and the like. Thus a gun at the head may be a good reason for handing over one's wallet, but not a good cognitive reason.

Choice based on good cognitive reasons is one aspect of rationality. Given that this is how rationality is generally understood in contemporary philosophy of inquiry, I shall follow this usage in this chapter; so whenever I speak of rationality simpliciter, I mean cognitive rationality. I shall also have cause to mention instrumental and communicative rationality, which will retain both their adjectives and the definitions they received in Chapter 1.

The centrality of rationality and progress to received ideas about science may explain why the specter of relativism raised in the wake of Kuhn's (1970b) account of scientific revolutions was so frightening. Kuhn himself protests innocence of relativism (see, e.g., Kuhn, 1970a, pp. 259-66).