This book is a seminal work that presents the author's theories on human sexuality, including his concept of sexual development through psychosexual stages. It explores topics such as the sexual aberrations, infantile sexuality, and the transformation of puberty. The author argues that sexual drive is present from birth, and that children go through several stages of sexual development. He also discusses the idea of sexual perversions and their origins. This book is considered a foundational text in the field of psychoanalysis.

"Psychology of the Unconscious" is a pioneering work that explores the complex landscape of the human unconscious, introducing theories that would later become central to understanding personality and human psychology. The book delves into the idea of the collective unconscious, archetypes, and the process of individuation. It further discusses the role of dreams, myths, and symbols in understanding and interpreting the unconscious mind. The author uses case studies and examples from various cultures to support his theories, offering a comprehensive view of the human psyche.

"Eros and Civilization" is a seminal work in critical theory that explores the interplay between societal structures and human desires. The book argues that the progress of civilization has necessitated the repression of basic human instincts and desires, as dictated by the performance principle governing capitalist societies, which prioritizes productivity and control over pleasure. Drawing on Freudian psychoanalysis, the author proposes the possibility of a non-repressive society where pleasure and work can coexist harmoniously. This work challenges traditional notions of utility and rationality in modern industrial societies, advocating for a liberation of human desires through aesthetic and libidinal expressions that could lead to a more fulfilling existence.

This book delves into the exploration of group dynamics and mass psychology. The author, a renowned psychologist, theorizes about the nature of groups, how they form, and how individuals within them behave. He also explores the concept of the 'ego' and its role within these group dynamics. The book provides a comprehensive analysis of group psychology, focusing on aspects such as leadership, suggestion and contagion, and the relationship between individual and group mind. It's a significant contribution to the understanding of mass movements and crowd behavior.

"Instincts and Their Vicissitudes" is a psychological analysis that explores the concept of instincts, their transformation, and their impact on human behavior. The book delves into the complexities of human instincts, proposing that they can be suppressed, redirected, or even reversed, and discusses their role in shaping our actions, desires, and anxieties. The author also examines the relationship between instincts and the conscious and unconscious mind, offering a comprehensive understanding of human psychology.

"On Narcissism" is an influential psychological work that explores the concept of narcissism, which is characterized by excessive self-love or self-centeredness. The author delves into the origins and development of narcissism, distinguishing between primary narcissism seen in infants who have not yet differentiated themselves from the outside world, and secondary narcissism in adults. The book argues that narcissism is a necessary stage in normal development, but can also be a characteristic of various mental health disorders if it persists into adulthood. The author also introduces the concept of the ego ideal, which plays a critical role in the development of the self and its relations to others.