Freud gets a bad rap. Most people think of him as pervert or an essential part of a good light bulb joke. But if you've ever sat across a therapist (or Skyped with one) and starting talking about your issues, you have Freud to thank. He invented the concept psychoanalysis, which has morphed into talk therapy.
And he did this way back in 1896. People still traveled by horse and buggy. In Paris, where Freud was studying, the new Eiffel Tower was the tallest structure in the world. The American Psychological Association was only four years old, and the first printing of the DSM was still 50 years away.
Before his big breakthrough, Freud was using hypnosis with patients. They discovered that talking about symptoms while hypnotized made them feel better. One patient, known as Anna O., called it the “talking cure.” Freud decided to take the “talking cure” further and found that his patients’ dreams were clues into their subconscious. He believed that neuroses were rooted in traumatic experiences from a patient's’ past. If he could get a person talking about it, they could confront it and move on. He then abandoned hypnosis and psychoanalysis was born.
It was the idea that talking could help a patient solve their issues and improve their behavior that was truly groundbreaking. He should have probably retired at that point, but he continued to explore a handful of theories-- some which he may have been better off repressing.