What Theory Is

The word theory covers a multitude of virtues and vices, sometimes counting as knowledge and sometimes contrasting with knowledge. But theory is as important as observation in science. We all take force, gravity, electrons, mass, and continental drift as genuine aspects of reality even though they are theoretical rather than observational (empirical) features. We all also recognize that the concept of luminiferous ether that was generally accepted at the outset of the nineteenth century is a theoretical concept that was discarded because of the Michelson-Morley experiment. The paradigm for scientific theory is Newton's theory of force, which incorporates the two theoretical concepts of force and gravity. Huygens formulated the laws of centrifugal force, Galileo the laws of freely-falling bodies, and Kepler the laws of planetary motion. Newton showed that each was a special case of the general laws of motion. He thereby integrated three apparently disparate fields of mechanics, explained the empirical laws by subsuming them under the general laws of the theory of force, and provided a heuristic model for further explanations. The best theories are explanatory, integrative, and heuristic. Most scholars recognize this paradigm. Nonetheless, theories today are too varied to come under any single rubric. A particular danger in the humanities and social sciences is that explanations there invariably have a moral dimension, raising the specter of moralism hidden in any and every theory. This essay articulates the paradigm and the cautions without attempting to evaluate grand theory in folkloristics.