terra incognita

Behold me now in the full career of my voyage of discovery, exploring the James River in the steamboat, on a clear, hot fifteenth of June, and looking with a sagacious perspicacity on the commonest sights of this terra incognita.

The concept of the unconscious or an inner terra incognita, an unknown country of the psyche that precedes and predicates the Cartesian subject, the focal point of rational consciousness, was a revolutionary idea.