Keller and Shoenfeld�s Principles of Psychology, published in 1950, was written as an introductory text to be used in the two-semester Psychology 1-2 course at Columbia University. It is a systematic approach in that a small number of functional relations described in B. F. Skinner�s The Behavior of Organisms are introduced and then used throughout to interpret the topics presented in a typical introductory psychology course. K & S was widely influential in familiarizing psychologists and others with the nature and general relevance of Skinner�s approach. It is an outstanding example of clear and interesting technical writing, and its style and topic arrangement have been the basis for a number of subsequent texts. Although old by textbook standards, it is still one of the easiest ways to acquire an accurate repertoire in the science of behavior.
