In recent decades, much work has been directed toward clarifying the logical relations among various sciences. Because of an emphasis on the logical aspects of interfield relations, the issue of scientific unity often wore a distinctly logical mantle.1 For example, Robert Causey, a prominent philosopher of this tradition, has linked scientific unity and progress to a project of successive microreductions. He states, “Other things being equal, we tend to feel that our understanding of a class of phenomena increases as we develop increasingly general and intuitively unified theories of that class of phenomena. It is therefore natural to consider the possibility of one very general, unified theory which, at least in principle, governs all known phenomena.” (1977, p. 1)

Kinds of unity separable from reductive logical unity have, of course, been proposed; these include reductive and nonreductive unities of method, translation, and ontology. For example, J.A. Fodor (1974) has argued for a broad kind of ontological unity of token physicalism, and against type reduction.