ABSTRACT
Theory is contrasted both with practice and with fact; it also stands over against experience. Theoretical concepts are contrasted with observational ones, and theoretical laws with empirical generalizations. A concatenated theory is one whose component laws enter into a network of relations so as to constitute an identifiable configuration or pattern. A hierarchical theory is one whose component laws are presented as deductions from a small set of basic principles. The theory of relativity, Mendelian genetics, and Keynesian economics may be taken to exemplify hierarchical theories. A classification of theories with which the preceding one is often confused is that into field theories and monadic theories. A theory may take as fundamental a system of relations among certain elements, explaining the elements by reference to these relations, or it may give primacy to relate, explaining the relations by reference to the attributes of what they relate.
