Beyond the Pleasure Principle (German: Jenseits des Lustprinzips) is a 1920 essay by Sigmund Freud that marks a major turning point in his theoretical approach. Previously, Freud attributed most human behavior to the sexual instinct (Eros or libido). With this essay, Freud went "beyond" the simple pleasure principle, developing his theory of drives with the addition of the death drive(s) (Todestrieb[e])[1] (often referred to as "Thanatos").