Five Fascinating Facts About Carl Jung

He thought he was two people (sort of) and more things you didn’t know about the pioneering psychologist

Jung's interest in the subconscious was a driving force in his work. Wikimedia Commons

Carl Jung was born on this day in 1875 in Thurgau, Switzerland. Some years later, he became the world-renowned founder of analytical psychology, a branch of the discipline that focuses on a person’s inner life to help understand how they think and any problems they may be facing.

It should come as no surprise, then, that Jung himself was quite a complicated person. Learn more about his quests for knowledge and self with these five lesser-known facts:

Jung coined “introvert” and “extrovert”

The terms “introverted” and “extraverted” (Jung spelled the latter with an a, though the dominant spelling in the U.S. now uses an o) first appear in Psychological Types, a book which Jung published in German in 1921. “In his model, differences between the personalities basically boil down to energy,” writes Joseph Bennington-Castro for io9.

Introverts, as Jung wrote, get their energy from their own self-dialogue and defend themselves “against external claims” on their energy with shyness or other means. Extroverts, on the other hand, are “friendly and accessible characters” who are constantly looking outward for their energy.

This theory has been a basis for everything from the Myers-Briggs Type Indicator to memes about canceling plans or hiding in the bathroom at parties. But Jung didn’t think anyone could be all introvert or all extrovert, Bennington-Castro writes: “‘There is no such thing as a pure introvert or extrovert,’” he reportedly said. ‘Such a person would be in the lunatic asylum.’”

Jung wrote a book on UFOs

Flying Saucers: A Modern Myth of Things Seen in the Skies was published in 1959.

The book's text, however, proved that Jung was far more interested in what rumors about aliens said about the human mind than whether the aliens themselves actually existed.

He collaborated with a Nobel-winning physicist

Jung had an “unlikely friendship” with theoretical physicist Wolfgang Pauli, writes Maria Popova for Brain Pickings. Pauli, who is known for first proposing the neutrino, was interested in dream analysis, but his friendship with Jung went beyond that. “Their conversations and correspondence went on to explore fundamental questions regarding the nature of reality through the dual lens of physics and psychology,” writes Popova.  Their years-long correspondence led Jung to come up with the idea of synchronicity or “meaningful coincidences.”

He speculated on the occult

Jung’s relationship with Pauli also led the pair to dive into the world of the occult. Amanda Gefter writes for New Scientist:  

The two sat for hours on end in Jung’s gothic-like mansion on the shores of Lake Zurich, dining on fine foods, drinking vintage wine and smoking the finest cigars while discussing topics from physics and whether there is a cosmic number at the root of the universe to psychology, ESP, UFOs, Armageddon, Jesus, Yahweh and Pauli’s dreams.

He thought he was two people (sort of)

Jung’s great innovation was taking his inner life seriously. This led him down some interesting pathes, writes Mark Vernon for The Guardian–like identifying two people within himself. He called them No. 1 and No. 2.

“No 1 was the child of his parents and times,” Vernon writes. “No 2, though, was a timeless individual, ‘having no definable character at all–born, living, dead, everything in one, a total vision of life.’”

Later in his career, No. 1 and No. 2 provided the basis of his ideas of ego and self.

Get the latest stories in your inbox every weekday.