FUNCTION AS CAUSE AND EFFECT

For both Hempel and Nagel, the point of departure for an understanding of functional explanation is the technique of functional analysis as applied in biology (primarily physiology) and social science (primarily cultural anthropology). In functional analysis, as Hempel puts it, a part of a complex biological or social system is studied in relation to the role it plays “in keeping the given system in proper working order or maintaining it as a going concern.” Nagel analyzes functions in terms of the “contributions of various parts of the system to the maintenance of its global properties or modes of behavior” and in terms of the function bearer's support for the “characteristic activities” of the system. The system's parts are viewed as means to ends in an attempt better to understand their causal roles in the system studied. Either a structural subsystem is isolated and its contribution to some capacity of the aggregate system is determined, or a function in or for the system is ascertained or postulated and a structure sought that might fulfill or perform it. For instance, one might take a structure in the cell, say mitochondria, and ask what their function is:What do they do? What are they there for, etc.? Or one can take a function, say energy conversion, and ask whether there is a power source in the cell: Is there some specific structure in the cell that converts energy? As a technique for gaining a better understanding of the system or as a heuristic regulative principle to guide the search for deterministic connections or relevant statistical correlations, functional analysis is uncontroversial.