Classification of Arts and Early Modern Sciences

To understand the concept of classification in the early modern period, it is necessary to first understand the conceptual framework the early moderns inherited from their predecessors. The world prior to 1600 was still largely Aristotelian. Aristotle (384–322 B.C.E.) provided a classification scheme based on matching a basic kind (species) with a set of distinguishing characteristics (differentia) in order to sort things in the world. Thus a human individual is a rational animal. That is, a human is of the kind "animal" but is distinguished from all other animals by rationality. This example reveals an underlying assumption of Aristotle's system: genuine classification provides definitions. When a thing is properly classified, it is defined. Definition, in turn, relies on the concept of essences. An essence is a property a thing must have to be what it is. Thus one might say that being rational is essential to being human; an individual thing is simply not a human if it lacks rationality.

In Aristotle is also found the first division between the arts and sciences. The distinction is modeled on the natural/artificial divide. Scientia concerns demonstrable and certain knowledge derived from nature. In nature, things develop according to natural internal principles of change (entelechies). Something is artificial if it changes because of an external source—like some clay becoming a sculpture because of a craftsman's work. Sculptures are artificial because they do not possess internal principles of change. They are what they are because someone or something else altered them. This distinction led Aristotle to characterize science as an enterprise whose goal is to account for the internal causes or explanatory principles we find in nature. Since this goal is reached by definition (asserting the essences of things), one discovers that appropriate classification is in fact the scientific enterprise—the process of acquiring knowledge. (See Posterior Analytics, in Complete Works, book 2, especially 93a1–10).