This document discusses various theories of motivation in the workplace. It covers: 1) Definitions of motivation and an overview of three categories of motivational theories - internal, process, and external. 2) Summaries of several influential early philosophers' perspectives on motivation including Max Weber, Sigmund Freud, and Adam Smith. 3) Descriptions of prominent motivational theories including Maslow's hierarchy of needs, McGregor's Theory X and Y, Herzberg's two-factor theory, and expectancy theory. 4) Discussion of additional concepts like equity theory, social exchange theory, and causes of motivational problems.