The document discusses various defense mechanisms used by the ego to protect itself from anxiety and unconscious impulses. It categorizes defenses into narcissistic, immature, neurotic, and mature types. Narcissistic defenses include denial, distortion, and projection used by psychotic individuals. Immature defenses such as acting out, hypochondriasis, passive aggression, regression and somatization are used by adolescents and non-neurotic patients. Neurotic defenses like displacement, intellectualization, rationalization, reaction formation, and repression are used by patients with OCD and hysteria under stress. More mature defenses are altruism, humor, suppression, sublimation, and compensation.