Definition in Aristotle’s Concept of Science

Aristotle’s concept of definition in Posterior Analytics represents a crucial component of the demonstrative science and in various forms determines the shape of his philosophical and scientific inquires. Although, the whole second book of this treatise is devoted to the systematic explanation of the forms of definition, full clarification of the role of definition reveals itself through the context of Aristotle’s concept of science. The aim of this paper is to introduce two main methods of definition on the basis of this concept.

The form of definition is mostly shaped by the nature of objects, which enter the scientific inquiry. At first it is necessary to acquire the definitions of elementary objects and properties which constitute the object of science. In this meaning the definitions pose as one of the immediate starting-points of scientific syllogism. The position of so-called immediate definitions is most significant for their purpose is not only to consolidate the meanings of elementary terms of the scientific language. Aristotle’s methodology of science is built upon essentialist foundations and thus the definitions aim to grasp all the necessary properties of the examined specie while excluding all those properties which are accidental to it. It follows that there is only one complete and adequate definition applicable to specie which allows the scientist to create a reliable foundation for the demonstrative phase of inquiry by acquisition of true premises which fully describe their object.

Syllogistic definitions stand at the other end of the process of scientific inquiry. In contrast to the first type of the object of definition their objects are complex and essence is unapparent. For the aim of defining is to grasp the essence Aristotle chooses to use demonstration as a tool if it's uncovering. In this context he presents the examples of natural phenomena of eclipse and thunder which cause is different from them to show the need for a specific approach. On the basis of Aristotle’s explanations this paper analyses these two types of defining as an integral part of scientific method and a natural result of the need to fully grasp the essence of the examined object.