The document describes various defense mechanisms used by the ego or unconscious mind to minimize anxiety and protect itself. It categorizes defenses into four levels from most pathological to most mature. Level 1 includes denial, distortion, and delusional projection. Level 2 contains defenses like fantasy, projection, and hypochondriasis. Level 3 involves displacement, dissociation, intellectualization and reaction formation. The most mature Level 4 defenses include altruism, anticipation, humor, identification, introjection, and sublimation.