Will to powerA basic element in Nietzsche's philosophical outlook is the will to power (der Wille zur Macht), which provides a basis for understanding human behavior—more so than competing explanations, such as the ones based on pressure for adaptation or survival. More often than not, self-conservation is but a consequence of a creature's will to exert its strength on the outside world.
In presenting his theory of human behavior, Nietzsche also addressed, and attacked, concepts from philosophies popularly embraced in his days, such as Schopenhauer's notion of an aimless will or that of utilitarianism. Utilitarians claim that what moves people is mainly the desire to be happy, to accumulate pleasure in their lives. But such a conception of happiness Nietzsche rejected as something limited to, and characteristic of, the bourgeois lifestyle of the English society, and instead put forth the idea that happiness is not an aim per se—it is instead a consequence of a successful pursuit of one's aims, of the overcoming of hurdles to one's actions—in other words, of the fulfillment of the will.
Related to his theory of the will to power, is his speculation, which he did not deem final, Other scholars disagree that Nietzsche considered the material world to be a form of the will to power. Nietzsche thoroughly criticized metaphysics, and by including the will to power in the material world, he would simply be setting up a new metaphysics. Other than aphorism 36 in Beyond Good and Evil, where he raised a question regarding will to power as being in the material world, it was only in his notes (unpublished by himself), where he wrote about a metaphysical will to power. Nietzsche directed his landlord to burn those notes in 1888 when he left Sils Maria for the last time.