Book excerpt: The Enlightenment of Sympathy reclaims the sentimentalist theory of reflective autonomy as a resource for enriching social science, normative theory, and political practice today. The sentimentalist description of the reflective process is more empirically accurate than the competing rationalist description, and can guide scientists investigating the processes by which the mind formulates moral and political principles. Yet the theory is much more than merely descriptive, and can also contribute to the philosophical project of finding principles--including principles of justice--that wield genuine normative authority. Enlightenment sentimentalism demonstrates that emotion is necessarily central to our civic life, and shows how our reflective sentiments can counterbalance the unreflective feelings that might otherwise lead our political principles astray.