The aim of this study is to introduce in detail the model of descriptive definition of Stephen C. Pepper.
After an outline of his analysis of nominal definitions, Pepper''s own conception of descriptive definition is presented. Further on, the study seeks to reveal deeper connections of this model to Pepper''s account of cognitive situation based on the dynamic and reciprocal relation between uncritical knowledge (common sense) and critical knowledge.
Finally, the potentially dangerous consequences of ignoring the proper nature and status of definition are discussed.