The Apollonian and Dionysian is a philosophical and literary concept, or dichotomy, based on certain features of ancient Greek mythology. Many Western philosophical and literary figures have invoked this dichotomy in critical and creative works.
In Greek mythology, Apollo and Dionysus are both sons of Zeus. Apollo is the god of reason and rational thinking, while Dionysus is the god of the irrationality and chaos, and appeals to emotions and instincts.
The Greeks did not consider the two gods to be opposites or rivals, although often the two deities were entwined by nature.
Although the use of the concepts of the Apollonian and Dionysian is linked to Nietzsche's The Birth of Tragedy, the terms were used before him in German culture. The poet Hölderlin spoke of them, while Winckelmann talked of Bacchus, the god of wine.
Nietzsche's aesthetic usage of the concepts, which was later developed philosophically, first appeared in his book The Birth of Tragedy, which was published in 1872. His major premise here was that the fusion of Dionysian and Apollonian "Kunsttriebe" ("artistic impulses") form dramatic arts, or tragedies. He goes on to argue that this fusion has not been achieved since the ancient Greek tragedians. Nietzsche is adamant that the works of Aeschylus and Sophocles represent the apex of artistic creation, the true realization of tragedy; it is with Euripides that tragedy begins its downfall ("Untergang"). Nietzsche objects to Euripides's use of Socratic rationalism (the dialectic) in his tragedies, claiming that the infusion of ethics and reason robs tragedy of its foundation, namely the fragile balance of the Dionysian and Apollonian.