What did Freud say about the rational and irrational?

Sigmund Freud is credited with the discovery of the unconscious mind that if allowed, would cause people to participate in activities that are considered to be against the natural social order, for instance, murder. With this discovery, Freud dismissed the idea that man has a fully rational mind. He further suggested that human behavior is a product of the interaction between the rational and irrational processes conceived by our mind. This led to his definition of the three aspects of personality; Id, Ego, and the Superego.

The Id embodies the irrational part of the mind and forms the driving force behind what we want and the pleasure that comes with the satisfaction of those particular wants. The Ego, on the other hand, represents the rational part of the mind and forms the driving force behind the reality that we can’t always have what we want. The Superego, which develops last, is the part of the mind that records and stores values learned from the environment. It functions by attempting to enforce the rules learned.

Freud asserted that the Rational (Ego) and Superego function in the conscious while the irrational (Id), functions in the unconscious.