The ninth turn developed in immediate succession to the eighth and is the discovery of the unconscious, the flip side of consciousness, so to speak. The unconscious first appears as a dark reservoir beyond consciousness, a kind of inner transcendence from which conscious experience rises. While this dimension has long been indigenous to Buddhism and Hinduism, it has only become an integral part of Western experiential culture since the 19th century.
From Leibniz and Baumgarten
The Enlightenment considered the mind as a transparent terrain. Leibniz, however, doubted that all perceptions were permanently conscious to us. Ever more philosophers such as Hume, Wolff, and Platner shared his reservations. Baumgarten was the first to assign the unconscious a specific place in the psyche. He called it the “bottom of the soul.” His idea quickly caught on.
to Schopenhauer and Nietzsche
At first, leading theorists such as Kant, Fichte, Schelling, and Hegel considered the unconscious to be only an intermediate stage on the way to conscious reflection. Finally Schopenhauer realized that it was a genuine dimension. Thus he created the first theory of the unconscious. By the middle of the nineteenth century, the unconscious was a popular idea, disseminated by Maine de Biran, Eduard von Hartmann, and Nietzsche in particular.
With Freud & Jung from Method to Institutions
Sigmund Freud, however, was the first to go from theory to method. His method is well known as psychoanalysis. Carl Gustav Jung expanded the field by adding the archetypes and the collective unconscious. Political implementations emerged as mass psychology, advertising, propaganda, and public relations. These, in turn, have stimulated new theoretical approaches developed in particular by Pareto, Lasswell, Schumpeter and the Critical Theory of the Frankfurt School.