In addition to free association, the concept of the unconscious was one of Freud’s major contributions. At that point in human history, it was assumed that people had conscious knowledge and control over everything they did or said. Freud, on the other hand, was able to demonstrate that there are many instances where we act without conscious knowledge or purpose.
One such example is dreams. Freud was fascinated with them. Dreams did not fit into the narrative of an ordered, logical mind, instead often coming across as nonsensical, baffling, and yet powerfully emotional.
But dreams were not the only instance of the unconscious breaking through — it happened in waking life, as well. Freud thought that there were “slips” in speech where the unconscious showed itself. He also thought that our characteristic ways of defending ourselves against strong unconscious impulses (like the desire to have sex) were evidence that those impulses were there. He wrote often about how society drove these impulses underground.
Why is the unconscious important to understand, as a concept that can help you resolve your psychological hang-ups and begin living a more intentional life? Well, Freud thought the entire goal of therapy was to make the unconscious conscious, and there are many approaches today that rely primarily, or at least heavily, on this benefit. The idea is that you cannot act intentionally unless you know why you are acting a certain way — and sometimes the only way to figure out that why is to explore your unconscious motivations.