Final answer:
Jung applied the principle of 'compensation' to suggest a balance between various aspects of the self, including consciousness and unconsciousness, as well as extroversion and introversion, which are central to his theory of personality psychology.
Step-by-step explanation:
Carl Jung applied the principle of compensation to psychic energy by proposing that there is a tendency toward maintaining a balance or equilibrium in the personality. According to Jung, this balance involves the equilibrium between different aspects of the self, such as conscious and unconscious thoughts, extroversion and introversion, and the integration of the collective unconscious with personal consciousness. Jung's concepts of extroversion and introversion have been considered his most critical contributions to personality psychology, serving as forerunners to later models of personality, including the widely known Myers-Briggs Type Indicator (MBTI).