Freud and the Psychodynamic Perspective Learning Objectives By the end of this section, you will be able to: Describe the assumptions of the psychodynamic perspective on personality development Define and describe the nature and function of the id, ego, and superego Define and describe the defense mechanisms Define and describe the psychosexual stages of personality development Sigmund Freud — is probably the most controversial and misunderstood psychological theorist. There was no such thing as a degree in psychology at the time that he received his education, which can help us understand some of the controversy over his theories today. However, Freud was the first to systematically study and theorize the workings of the unconscious mind in the manner that we associate with modern psychology. In the early years of his career, Freud worked with Josef Breuer, a Viennese physician. Launer, Anna O.