The psychoanalytic perspective arose from subsequent psychoanalytic theories (1901, 1924, and 1940) after decades of interactions with clients using an innovative procedure developed by Sigmund Freud that required lengthy interactions verbal conversations with patients during which Freud probed deeply into their lives. Simply put, the psychoanalytic perspective sought to explain personality, motivation, and psychological disorders by focusing on the influence of early childhood experiences, unconscious motivations and conflicts, and the methods people use to cope with their sexual and aggressive impulses . The biological perspective instead examines the physiological bases of behavior in humans and animals. It proposes that the functioning of an organism can be described in terms of bodily structures and biochemical processes that cause behavior. This article attempts to examine the similarities and differences between the psychoanalytic perspective and the biological perspective by primarily focusing on the fundamental assumptions and characteristics of these perspectives, as well as their individual strengths and weaknesses. The biological perspective examines how brain processes and other bodily functions regulate behavior. He emphasizes that the brain and nervous system are critical to understanding behavior, thinking, and emotions. Thoughts and emotions are believed to have a physical basis in the brain. Electrical impulses zip through brain cells, releasing chemicals that allow us to think, feel and behave. René Descartes (1596–1650) wrote an influential book (De Homine [On Man]) in which he tried to explain how the behavior of animals, and to some extent the behavior of humans, could be like...... middle of sheet ......me Irving B. WeinerFreud, S. (1957b). Some character types encountered in psychoanalytic work. In J. Strachey (ed. and trans.), The standard edition of the complete psychological works of Sigmund Freud (Vol. 14, pp. 309–333). London: Hogarth Press. (Original work published 1916) McKinley, J. and Fryer, D. (2004), Higher Psychology: Approaches and Method. KEEGAN, G. (2002) Hodder and Stoughton, London, 298 ppIntroduction to psychology 5th ed - Morgan and kingScience and understanding of psychology Barry d. Smith (1998) McGraw-HillPsychology that makes sense david A. STATT - NEW YORK- HARPER AND ROW 1977HANDBOOK of PSYCHOLOGIA VOLUME 5 PERSONALITY AND SOCIAL PSYCHOLOGYTheodore Millon, Melvin J. Lerner/ Irving B. Weiner: Editor-in-ChiefWaiten,W. , (2007) Seventh edition Themes and variations in psychology. University of Nevada, Las Vegas: Thomson Wadsworth.