The definitions of self are perhaps as many as the theorists who have thought about it. Beside the bodily activities of the self of a person, including their brains and central nervous system, the self is made up of at least two major aspects. These can be referred to as the machinery of the self and the mental state or the idea of me. The machinery of the self involves all unconscious, unreferenced actions of the body, including its physiology and its processing of information that in turn includes cognitions and emotions, which are unavailable to consciousness. The mental state, or the idea of me, is that part of the self that can make reference to itself. It includes what is referred to as explicit consciousness. In the animal kingdom, the ability to reflect upon the person constitutes perhaps the most unique feature of the human self.
See Competence (psychology), Consciousness, Ego, Identity development, Internalizing disorders/problems, Mastery, Narcissism, Personal literacies, Self-competence, Self-concept, Self-conscious emotions, Self-efficacy, Self-esteem, Self-gratification, Self-perception, Self-recognition, Self-regulation