Economist-philosopher Amartya Sen's writings on social and political issues have attracted wide audiences. Section 2 introduces his contributions on: how people reason as agents within society; social determinants of people's (lack of) access to goods and of the effective freedoms and agency they enjoy or lack; and associated advocacy of self-specification of identity and high expectations for ‘voice’ and reasoning democracy. Section 3 considers his relation to social theory, his tools for theorizing action in society, and his limited degree of (...) attention to work by sociologists and to capitalism and power structures. Section 4 characterizes a style marked by conceptual refinement, emphases on complexity and individuality, including personal individuality, and reformist optimism. Section 5 shows the features from Sections 3 and 4 at work in his conception of personhood that advocates freedom to make a reasoned composition of personal identity. Similarly, Section 6 addresses his conception of public reasoning and neglect of the sociology of democracy. It contrasts the ideal of a reasoning polity with features in many countries. Sen's programmes for critical autonomy in personhood and for reasoned politics play, nevertheless, a normic role, while his analytical formats help investigation of obstacles to more widespread agency, voice, and democratic participation. (shrink)