Friedrich Nietzsche (1844-1900), German philosopher. Nietzsche devised a new system of values to account for the advances in biology and psychology. He considered the individual as a biological specimen and applied Charles Darwin's evolutionary theories to human psychology. He taught that a creative surge or "will to power", based on a biological urge for excellence, was the main motive force behind human evolution. Nietzsche influenced many psychologists, including Freud, by claiming that human motives are to be found in instincts rather than reason. Nietzsche's ideas have been a major influence on 20th century thinking. Print by Hans Olde between 1870 to 1917.