Human, all too human (Penguin Books)

Written after Nietzsche had ended his friendship with Richard Wagner and had been forced to leave academic life through ill health, Human, All Too Human (1878) can be read as a monument to his personal crisis. It also marks the point when he matured as a philosopher, rejecting the German romanticism espoused aby Wagner and Schopenhauer and instead returning to sources in the French Enlightenment. Here he sets out his unsettling views in a series of 638 stunning aphorisms - assessing subjects ranging from art to arrogance, boredom to passion, science to vanity and women to youth. This work also contains the seeds of concepts crucial to Nietzsche's later philosophy, such as the will to power and the need to transcend conventional Christian morality. The result is one of the cornerstones of his life's work.