In the 21st century, Carl Gustav Jung (1875-1961) remains one of the key figures in the field of analytical psychology - and Psychological Types, or The Psychology of Individuation, published in 1921, is one of his most influential works. It was written during the decade after the publication of Psychology of the Unconscious (1912), which effectively ended his friendship and collaboration with Sigmund Freud.

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.

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.

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.

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.

The Origins and History of Consciousness draws on a full range of world mythology to show how individual consciousness undergoes the same archetypal stages of development as human consciousness as a whole. Erich Neumann was one of C. G. Jung's most creative students and a renowned practitioner of analytical psychology in his own right. In this influential book, Neumann shows how the stages begin and end with the symbol of the Uroboros, the tail-eating serpent.

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. The result is an absorbing piece of self-analysis: a frank statement of faith, philosophy, and principles from one of the great explorers of the human mind.

Eating is an indispensable human activity. As a result, whether we realize it or not, the drive to obtain food has been a major catalyst across all of history, from prehistoric times to the present. Epicure Jean-Anthelme Brillat-Savarin said it best: "Gastronomy governs the whole life of man."

Holocaust survivor Viktor E. Frankl is known as the founder of logotherapy, a mode of psychotherapy based on human's motivation to search for meaning in his life. The author discusses his ideas in the context of other prominent psychotherapies and describes the techniques he uses with his patients to combat the "existential vacuum".

When Newton discovered the law of gravity, he unified the rules governing the heavens and the Earth. Since then, physicists have been placing new forces into ever-grander theories. But perhaps the ultimate challenge is achieving a monumental synthesis of the two remaining theories—relativity and the quantum theory. This would be the crowning achievement of science, a profound merging of all the forces of nature into one beautiful, magnificent equation to unlock the deepest mysteries in science: What happened before the Big Bang?