Central to understanding evil in Nietzsche philosophy was the idea of affirmation of life. Nietzsche was known to question everything. He questioned socially accepted doctrines and was referred to as the first existentialist philosopher. Nietzsche's education and associations with other philosopher's defined his thinking for what later became an understanding of evil in Nietzsche's Philosophy. The basis for Nietzsche philosophy of good and evil can best be explained by Nietzsche's belief that truth is nothing more than the invention of fixed conventions for practical purposes.