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.

Sigmund Freud (1856-1939) is remembered as the father of psychoanalysis. Civilization and Its Discontents (1930) is one of his key works, written three decades after his seminal book The Interpretation of Dreams. In it he considers the conflict between the needs of the individual acting both egotistically and altruistically in the pursuit of happiness and the myriad demands of civilised society and the ensuing tensions this clash of needs and demands generates.

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 most important book ever written in psychology.

As former tutor and adviser to Emperor Nero, philosopher and statesman Seneca was acutely aware of how short life can be - his own life was cut short when the emperor ordered him to commit suicide (for alleged involvement in a conspiracy). And Seneca proved true to his words - his lifelong avowal to Stoicism enabled him to conduct himself with dignity to the end. During his rich and busy life, Seneca wrote a series of essays that have advised and enriched the lives of generations down to the present day.

In the beginner's mind there are many possibilities, but in the expert's there are few. So begins this most beloved of all American Zen works....

Kant is arguably the most influential modern philosopher, but also one of the most difficult. Roger Scruton tackles his exceptionally complex subject with a strong hand, exploring the background to Kant's work and showing why the Critique of Pure Reason has proved so enduring.

Awe and exhilaration—along with heartbreak and mordant wit—abound in Lolita, which tells the story of the aging Humbert Humbert's obsession for the nymphet Dolores Haze. Lolita is also the story of a hypercivilized European colliding with the cheerful barbarism of postwar America.

The Red Book, published to wide acclaim in 2009, contains the nucleus of C. G. Jung's later works. It was here that he developed his principal theories of the archetypes, the collective unconscious, and the process of individuation that would transform psychotherapy from treatment of the sick into a means for the higher development of the personality.

At the beginning of his career, Joseph Campbell developed a lasting fascination with the cultures of the Far East, and explorations of Buddhist and Hindu philosophy later became recurring motifs in his vast body of work. However, Campbell had to wait until middle age to visit the lands that inspired him so deeply. In 1954, he took a sabbatical from his teaching position and embarked on a year-long voyage through India, Thailand, Cambodia, Burma, Hong Kong, Taiwan, and finally Japan.