These essays by eminent economist Prasanta K. Pattanaik deal with two distinct areas: (i) the theory of decision making by individuals; and (ii) welfare economics and the theory of social choice. The papers in the first group are all concerned with situations outside the conventional frameworks of rational choice under perfect certainty and uncertainty. Essays in the second group are concerned with the classical problem of aggregation of preferences and welfare judgments. Some deal with the formal modeling of individual rights, and the measurement of freedom--concluding with measurement of living standards. The volume will be useful to researchers and students of welfare economics. Besides economists, students and teachers of psychology, political science, and philosophy will also find them of interest.