Here are three key works by Sigmund Freud which, published in the first decades of the 20th century, underpinned his developing views and had such a dramatic effect on world society. In the uncompromising Three Essays on the Theory of Sexuality (1905), he declared that 'sexual aberrations' are not limited to the insane but exist in 'normal' people to a greater or lesser degree. The three essays are divided between sexual perversions, childhood sexuality and puberty.

This series of 28 lectures was given by Sigmund Freud (1856-1939), the founder of psychoanalysis, during the First World War and first published in English in 1920. The purpose of this general introduction was to present his work and ideas - as they had matured at that point - to a general public; and even though there was to be considerable development and change over the ensuing years, these talks still offer a valuable and remarkably approachable entry point to his revolutionary concepts.

The Interpretation of Dreams by Sigmund Freud is one of the most significant books of the 20th century. Though dreams and their role in human consciousness have been a continuing thread in religion and art and life down the centuries, Freud's look at the subject through the prism of his emerging practice and study of psychoanalysis provided a startlingly new and challenging perspective.

The Psychopathology of Everyday Life, which appeared first in 1901 and was then expanded in a series of subsequent editions, has proved to be one of Freud's most popular works, and one of his most influential during his lifetime. It was here that he proposed that many slips and errors of memory common to the average man in everyday life actually signals unconscious issues that beset the individual, and, if examined, can be extremely revealing.

One of Freud's central achievements was to demonstrate how unacceptable thoughts and feelings are repressed into the unconscious, from where they continue to exert a decisive influence over our lives. This volume contains a key statement about evidence for the unconscious and how it works, as well as major essays on all the fundamentals of mental functioning. Freud explores how we are torn between the pleasure principle and the reality principle, how we often find ways both to express and to deny what we most fear and why certain men need fetishes for their sexual satisfaction.

Sigmund Freud (1856-1939) reveals himself in this autobiography, which is simultaneously an account of the early history of psychoanalysis, to have been an outsider from the start. This fascinating account describes the journey of a young, Jewish doctor setting out to find his way in the world of professional medicine, his relationships and collaborations, friendships made and lost and his investigations into cocaine, hypnosis and the cathartic method which contributed to the evolution of his conceptual framework and practices.

In 1957, four years before his death, Carl Gustav Jung, psychiatrist and psychologist, began writing his life story. But what started as an exercise in autobiography soon morphed into an altogether more profound undertaking.

This 1920 essay by Sigmund Freud is considered to be one of his most complex writings. "Beyond the Pleasure Principle" marks a major departure in his theoretical approach. Freud had previously attributed most human behaviour to the sexual instinct (Eros or libido). In this essay, he went beyond the pleasure principle by adding the death drive (thanatos) as another instigator of human behavior.

Being and Time was published in 1927 during the Weimar period in Germany, a time of political, social and economic turmoil. Heidegger himself did not escape the pressures and his nationalism, and undeniable anti-Semitism in the following decades cast a shadow over the man, but not the work. Being and Time is not coloured by expressions of his later views (unlike other writings) and remains an outstanding document.  

Slavoj Žižek's first book is a provocative and original work looking at the question of human agency in a postmodern world. In a thrilling tour de force that made his name, he explores the ideological fantasies of wholeness and exclusion which make up human society. 

In On the Genealogy of Morals, subtitled "A Polemic", Nietzsche furthers his pursuit of a clarity that is less tainted by imposed prejudices. He looks at the way attitudes towards 'morality' evolved and the way congenital ideas of morality were heavily colored by the Judaic and Christian traditions.

Jacques Lacan was one of the most important psychoanalysts ever to have lived. Building upon the work of Sigmund Freud, he sought to refine Freudian insights with the use of linguistics and mathematics, arguing that "the structure of unconscious is like a language." He is widely misunderstood and often unfairly dismissed as impenetrable. In this clear, wide-ranging primer, Lionel Bailly demonstrates how Lacan’s ideas are still vitally relevant to contemporary issues of mental health treatment. Including coverage of developments in Lacanian psychoanalysis since his death, this is the perfect introduction to the great modern theorist.

Published first in 1912, Psychology of the Unconscious was one of the most important stepping stones in the development of Jung’s thought and practice. It has a long subtitle: A Study of the Transformations and Symbolisms of the Libido. A Contribution to the History of the Evolution of Thought. This expressed the underlying impetus - a break from the view of the libido and its functions as taught by Sigmund Freud, which Jung had earlier adopted. It was from this point that the two approaches, which came to be known as the Swiss and Viennese schools, emerged.

Modern Man in Search of a Soul is the classic introduction to the thought of Carl Jung. Along with Freud and Adler, Jung was one of the chief founders of modern psychiatry. In this book, Jung examines some of the most contested and crucial areas in the field of analytical psychology: dream analysis, the primitive unconscious, and the relationship between psychology and religion.

Perhaps one of the most revolutionary works of philosophy ever presented, The Phenomenology of Spirit is Hegel's 1807 work that is in numerous ways extraordinary. A myriad of topics are discussed, and explained in such a harmoniously complex way that the method has been termed Hegelian dialectic. Ultimately, the work as a whole is a remarkable study of the mind's growth from its direct awareness to scientific philosophy, proving to be a difficult yet highly influential and enduring work.