The unconscious is that part of the mind we are unaware of. The modern concept of the unconscious was developed by Sigmund Freud, who taught that guilt,shame and a strong sense of propriety push unwanted desires, drives or memories into the unconscious where they become unknown while still continuing to have an influence. Freud also taught that it was only by making the unconscious conscious that the individual could become psychologically happy and mature. This was to be done, he said, using the technique of free association, the analysis of dreams and with the guidance of a psychoanalyst. Although the concept of the unconscious is certainly valid and does not contradict the Buddhist understanding of the mind, it is not explicitly found in Buddhist psychology. There is a good reason for this. The Buddha discovered that by developing a strong, persistent, nonjudgmental mindfulness, and then turning it to the mind, it would reveal the most hidden recesses of the psyche. This being so, it was not necessary to make the sharp and ultimately arbitrary distinction between the conscious and the unconscious mind.
Buddhist and Freudian Psychology, Padmasiri de Silva,1975.