A hallmark of the ideology of the Enlightenment is the doctrine of social environmentalism. Its different modes are variations on the familiar theme-indeed as old as social speculation-of the malleability of human nature characterizing much of the thought of classical antiquity and continued by Renaissance figures like Machiavelli, Pico, Erasmus, More, and Vives. If man's being is partially plastic and each person's outlook and conduct result to some extent from upbringing, example, schooling, associations, and circumstances, then it follows that the human makeup can be shaped, at least to some extent, by action upon the social environment. To make happy, virtuous, and cooperative individuals dedicated to the common good, the social context must be rendered amenable to such ends. Social, political, and legal institutions and arrangements can be positive instruments in fashioning the human raw stuff according to some ideal model, either by gradual alteration and reform or by the radical restructuring of society. Socially subversive behavior, delinquency, and crime, or so it is maintained, can be appreciably reduced by refurbishing the institutional and legal setting. Depending upon the degree of malleability assigned to human nature, utopia, or something approaching it, is a distinct possibility. When given a chronological emphasis, the doctrine of social environmentalism during and after the Enlightenment is transformed into several brands of historicism, often with an incremental theory of human development entailing a pattern of the progressive interaction of individual and society, both changing in a dialectical process. We create and recreate ourselves by altering our social environment. A most significant realm of theory and practice was thus opened up by the Enlightenment's doctrine of social environmentalism, to become a major feature