Sun Tzu is a honorific title bestowed upon Sūn Wu (c. 544-496 BC), the author of The Art of War, an immensely influential ancient Chinese book on military strategy.

He is also one of the earliest realists in international relations theory. In the author's name, Sūn Wu, the character wu, meaning "military", is the same as the character in wu shu, or martial art. Sun Wu also has a courtesy name, Chang Qing (Cháng Qīng).

Voltaire (1694 1778) was a French man of letters and a leading figure of the Enlightenment, known for his outspokenness and polemical writings.

The philosophical novellas Candide and Zadig are among his most celebrated works.

Aristotle was born in the Macedonian city of Stagira in 384 BC, and died in 322. He studied in Plato's Academy in Athens and later became tutor to Alexander the Great, before establishing his own school in Athens, called the Lyceum. His writings, which were of extraordinary range, profoundly affected the whole course of ancient, medieval and modern philosophy. Many of them have survived, including The Nicomachean Ethics, The Politics and Poetics, among others.

Dale Carnegie, known as 'the arch-priest of the art of making friends', pioneered the development of personal business skills, self-confidence and motivational techniques.

His books most notably How to Win Friends and Influence People - have sold tens of millions worldwide and, even in today's changing climate, they remain as popular

The founder of psychoanalysis, Sigmund Freud (1856–1939) ranks among the most important figures in Western psychology. Freud is responsible for the theories of parapraxis (Freudian slips), dreams as wish fulfillment, the Oedipus complex, repression, the unconscious mind, and other ground-breaking concepts.

Hermann Hesse was born in Calw in 1877, a town in the north of the Black Forest. As a child he was constantly at odds with his religious upbringing and education.

His experiences of childhood, adolescence and the desire to break into the world as an artist would form the matter of his first three novels, Peter Camenzind, The Prodigy and Gertrude. Following an ever-present spiritual thirst, Hesse read widely on theosophy, Buddhism and the burgeoning field of psychoanalysis, even becoming a patient of Carl Jung.

This seeking is evident in some of his greatest novels, such as Demian, Steppenwolf, and Siddhartha. Little known outside of Germany at the time of his death in 1962 the arrival of the first English translation of Siddhartha in 1954 struck a chord with the counterculture movement of the 1960s. Soon after, Hesse became one of the most widely read and translated European authors of the 20th century. He was awarded the Nobel Prize for Literature in 1946.

Not much is known about the legendary LAO TZU, to whom authorship of the TAO TEH CHING is popularly attributed. Some scholars believe the author was an elder contemporary of Confucius.

The philosopher Friedrich Nietzsche was born in Prussia in 1844. After the death of his father, a Lutheran minister, Nietzsche was raised from the age of five by his mother in a household of women. In 1869 he was appointed Professor of Classical Philology at the University of Basel, where he taught until 1879 when poor health forced him to retire. He never recovered from a nervous breakdown in 1889 and died eleven years later.

Known for saying that 'god is dead,' Nietzsche propounded his metaphysical construct of the superiority of the disciplined individual (superman) living in the present over traditional values derived from Christianity and its emphasis on heavenly rewards. His ideas were appropriated by the Fascists, who turned his theories into social realities that he had never intended.

Plato ranks among the most familiar ancient philosophers, along with his teacher, Socrates, and his student, Aristotle.

In addition to writing philosophical dialogues - used to teach logic, ethics, rhetoric, religion, and mathematics as well as philosophy - he founded Athens' Academy, the Western world's first institution of higher learning.