Psychology is described as separatistic, divided into unrelated islands of knowledge even where unification would be possible. This separatism is seen as anachronistic, an indication of the preparadigmatic state of the science, Unresolved schisms in science help to perpetuate this divisivenessand incommensurability. The schisms are due in large part to the lack of unifying theory that would establish connections between presently unrelated bodies of knowledge. The author describes a method and philosophy of theory construction, the aim of which is the unification of various areas and theories of psychology as well as the resolution of traditional schisms in our science. He discusses the need to encourage efforts to create unified theory generally, such that additional examples of such theory emerge, as well as standards for evaluating these theories. Psychology has had the means for creating empirical knowledge in abundance, and it must now develop the conceptual tools to organize this knowledge.Looking back at the products of a science, one sometimes gets a picture of smooth, logical development. Looking ahead is another matter. Developments sometimes occur, at least at certain stages, that are not anticipated within the confining context of the contemporary science. Moreover, a new, advantageous development that opposes the accepted paradigm may go unseen or be rejected (Kuhn, 1962).It has been proposed (Staats, 1967(Staats, , 1968b(Staats, , 1975; Staats, Note 1) that our science is presently characterized by separatism, a feature that has a pervasive effect and that constitutes an obstacle to scientific progress. The concept of separatism describes our science as split into unorganized bits and pieces, along many dimensions. Divisions exist on the basis of theory, method, and the types of findings that are accepted, as well as on the basis of student training, organizational bodies such as divisions, journals, and individual strivings. Our field is constructed of small islands of knowledge organized in ways that make no connections with the many other existing islands of knowledge.