What is the human mind?
The human mind has been described in various models. One such model was developed by Carl Jung, a 20th century psychologist who developed depth psychology, that has been verified through the experiences of people in therapy, as well as through introspection such as in meditation. The model is composed of three parts: the ego consciousness, the personal unconscious and the collective unconscious.
Ego consciousness is the ordinary state of consciousness; a narrative of self-identity, a self-told inner story about who or what we are; the defiled mind identifies with the ego. The ego is both a content of our ordinary consciousness and its center. The ego exercises self reflection, the ability to separate the subject from the object; that is, to be aware of the contents of consciousness.
The personal unconscious underlies ego consciousness, not only influencing it but also exchanging contents with it. The personal unconscious consist of dissociated, repressed, forgotten or discarded contents that originated in ego consciousness, and which can return to ego consciousness under appropriate conditions. The defilements that are mentioned in the Pāli suttas are found in the personal unconscious.
The collective unconscious is the foundational segment, primordial, older in an evolutionary sense and shared by all human beings, it is the transpersonal. The structure and contents of the collective unconscious predate the rise of both ego consciousness and the personal unconscious and are independent of ego conscious experiences. Its contents can not cross into ego consciousness; however, they can still influence ego consciousness by way of dreams and visions.
Note that the personal and collective unconscious segments are only ‘unconscious’ from the perspective of ego consciousness, in that the ego cannot access them through introspection. But from their own perspective they are conscious in that they have experiential contents.