This article offers a description of dialectical thinking as a psychological phenomenon that reflects adult intellectual development. While relating this psychological phenomenon to the various dialectical philosophical perspectives from which the description is derived, the article conceptualizes dialectical thinking as a form of organization of thought, various aspects of which can be identified in individual adults' approaches to conceptualizing a range of problems, rather than as one particular stream of intellectual history. The article provides a range of examples of dialectical analyses, contrasting them with more formalistic analyses, in order to convey the power, adequacy, and significance of dialectical thinking for the sorts of challenges that this journal embraces. It suggests that events in all areas of life demand recognition of the limitations of closed-system approaches to analysis. Approaches based instead on the organizing principle of dialectic integrate dimensions of contradiction, change and system-transformation over time in a way that supports people's adaptation when structures under girding their sense of self/world coherence are challenged. Higher education and psychotherapy are considered as examples of potential contexts for adult intellectual development, and the conditions that foster such development in these contexts are discussed. The article as a whole makes the case for consciously attempting to foster such development in all our work as an approach to integration.