In parallel with the writing of his first book, The Birth of Tragedy, Nietzsche is investigating a second problem: the status of the true. The text he then wrote, From Truth and Lie in the Extra-Moral sense, leads to the most radical intellectual upheaval ever developed in philosophy: the questioning of the idea of objective truth, and the identification of illusion as the very condition of life. It is therefore the whole European culture, favouring theoretical knowledge, which becomes the object of questioning, and in particular its educational system.