The contemporary fields of interdisciplinary studies and the policy sciences have evolved over similar intellectual paths and timelines, beginning in the early 20th century. Both have their roots in professional efforts--within and outside the academy--to address numerous, growing, and complex problems that face humanity. The policy sciences' approach to integration via interdisciplinarity serves the civic and public processes of community and decision making that address these problems, while at the same time respecting the individual human being. This goal explicitly seeks dignity for all individuals in healthy environments. The policy sciences offer a framework and an intellectual toolbox with a fundamental set of operations to achieve integration via interdisciplinarity in the interests of problem solving. This framework guides interdisciplinarity in practical, teachable, and learnable terms, the history of which mirrors the evolution of interdisciplinary studies. A review of the policy sciences in the context of interdisciplinary studies emphasizes their shared heritage and raises important questions about how isolated communities of scholars and practitioners with a convergent evolution might collaborate to promote greater achievement of their common goals.