The term 'reduction' or reductionism refers to an analysis of some 'x' into presumably simpler elements or "more real" parts. In his book Religious Experience (Berkeley: University of California Press, 1985, pp. 196-97), Wayne L. Proudfoot identifies two sorts of reductionism, and he characterizes the first sort - descriptive reduction - as a mark of failure. Why? Because descriptive reduction will short-circuit the process of inquiry and prevent the achievement of the most basic aims of scholarly investigation.

On the other hand, Proudfoot commends the second sort of reductive procedure - explanatory reduction.

What's the difference? Timing is everything. At the beginning of inquiry any reduction discounts, disrespects, and impeaches the subject under investigation. The investigator's version overwhelms every other one. Whether a reduction is descriptive or explanatory depends on the point in a process of inquiry at which it takes place. Description, according to Proudfoot, must be preliminary and prerequisite to any further stage of investigation. Perhaps a couple of examples from everyday life will make this clear. In baseball, one cannot get safely home without getting on base in the first place. In Monopoly, in order to collect rent a player must first get property, improve it, and wait for another player to land on it.

Proudfoot proposes a two-step investigative strategy. The first (required and prerequisite) step is to attend to the "other" and enable oneself to give a bare description or empathetic account that avoids descriptive reduction. The second step is to go in for some particular version of explanatory reduction. Moreover, according to Proudfoot, the second step is the distinctive work of critical scholarship. It is the production of an interpretive (re)statement that "translates" and "recontextualizes" the material that was initially described in terms that would be recognized, acknowledged, and approved by the "other." The required first step is phenomenology - the task of neutral or empathetic description. The second step is critical scholarship in which the initial description (perhaps augmented by contextual or comparative information and certainly by selected theoretical perspectives) is turned into data, and the scholar subjects the data to a critical and creative analysis. This procedural proposal is what I call the Proudfoot Two-Step.

Descriptive reduction is the failure to identify an emotion, practice, or experience under the description by which the subject identifies it. This is indeed unacceptable. To describe an experience in nonreligious terms when the subject himself [or herself] describes it in religious terms is to misidentify the experience, or to attend to another experience altogether. . . . To describe the experience of a mystic by reference only to alpha waves, altered heart rate, and changes in bodily temperature is to misdescribe it. To characterize the experience of a Hindu mystic in terms drawn from the Christian tradition is to misidentify it. In each of these instances, the subject's identifying experience has been reduced to something other than that experienced by the subject. This might properly be called reductionism. In any case, it precludes an accurate identification of the subject's experience.

Explanatory reduction consists in offering an explanation of an experience in terms that are not those of the subject and that might not meet with his [or her] approval. This is perfectly justifiable and is, in fact, normal procedure. The explanandum is set in a new context, whether that be one of covering laws and initial conditions, narrative structure, or some other explanatory model. The terms of the explanation need not be familiar or acceptable to the subject. Historians offer explanations of past events by employing such concepts as socialization, ideology, means of production, and feudal economy. Seldom can these concepts properly be ascribed to the people whose behavior is the object of the historian's study. But that poses no problem. The explanation stands or falls according to how well it can account for all the available evidence.

Failure to distinguish between these two kinds of reduction leads to the claim that any account of religious emotions, practices, or experience must be restricted to the perspective of the subject and must employ only terms, beliefs, and judgments that would meet with his [or her] approval. This claim derives its plausibility from examples of descriptive reduction but is then extended to preclude explanatory reduction. When so extended, it becomes a protective strategy. The subject's identifying description becomes normative for purposes of explanation, and inquiry is blocked to insure that the subject's own explanation of his [or her] experience is not contested.