Reconstructing Reason: An Investigation of Moral Rationalism and the Normative Core of Critical Social and Political Theory

This thesis is an analysis of notions of practical reason at the heart of moral rationalism, broadly conceived. In the Western tradition, at least since the Enlightenment, most moral philosophers and political theorists have thought their task was to develop credible alternatives to the traditional justifications of norms, principles, and institutions based on settled tradition or divine authority. The prevailing enlightenment tendency was to insist that the best way to figure out how to live would involve, instead or in addition to other methods, a significant role for some kind of thinking process called practical reasoning. Today we face the dilemma that globalization in the face of diversity has made it increasingly impossible to ignore the absence of any settled tradition which could act as a foundation for moral, social, and political practice, while both modern and ancient conceptions of practical reason have fallen under suspicion (some of it well-founded). I seek to answer the question: under these conditions, can we still expect to find, in reason, a legitimate basis for our social and political norms and practices? I suggest we can. My approach is bracketed by what I claim to be two prevalent extremes. At one side there is the enlightenment and its scientistic heirs (particularly rational choice theory), and on the other, certain post-modern (over)reactions to the enlightenment failure, which allow rationality to lose its critical normative force. The constructive aim of this work involves drawing on leading contemporary thinkers who attempt to hang on to a connection between practical reason and normativity (particularly John Rawls, Jürgen Habermas, and Martha Nussbaum). They attempt this, I argue, by reacting to, and developing, landmark paradigms in the history of ideas about practical reason, particularly those of Aristotle, Hume and Kant. I then evaluate their attempts and synthesise their insights into a normatively critical account of moral rationalism, which I call the Discourse-Capabilities Approach, an approach that incorporates core insights of Aristotle, Hume, Kant, and their contemporary heirs, while avoiding what I claim are the main defects associated with each of these accounts.