Gruithuisen, 143, 144. Gurney, E., 224, note[109]. H. Hall, G.S., 186, note[102]. Hallucination, and illusion, 11, 109, 111, 112, 121; and subjective sensation, 63, 109, 121; sensory and motor, 66; nervous conditions of, 112-114; incomplete and complete, 113; as having either central or peripheral origin, 113; causes of, classified, 115; in sane condition, 116; in insanity, 118; visual and auditory, 119; dreams regarded as, 139, 151; hypnagogic, 143; after-dreams and ghosts, 183; of memory, 271; relation of, to errors of belief, 322; intuition of external world regarded as, 355. Happiness, feeling of, 200. Harmful, illusion as, 188, 229, 292, 339. Harmless, illusions as, 124, 292, 341. Hartley, D., 139, 256, note[124], 279. Hearing, as mode of perception, 34, 48; localization of impression in, 60; sense of direction in, 72; activity of, in sleep, 140; and muscular sense, 171. Heidenhain, Dr., 186-188. Helmholtz, H., 22, 23, note[7], 44, 51, 54 and note[22], 55, note[23], 57, 67, note[33], 78, note[39], 80, 85, note[43], 88, 90, 207, note[105]. Heraclitus, 137. Heredity, and illusion of memory, 280; action of, in perpetuating intuition, 359. Hering, E., 67, note[33]. Hodgson, Shadworth H., 347, note[153]. Holland, Sir H., 277. Hood, Thomas, 146. Hope, illusory. _See_ Expectation. Hoppe, Dr. J.I., 51, 58, note[26]. Horwicz, A., 145, note[85]. Hume, D., 355. Huxley, Professor T., 119, note[1]. Hyperaesthesia, 65. Hypnotism, 185. Hypochondria, 65. Hypothesis, as illusory, 310, 311. I. Idealism, 348. Identity, cases of mistaken, 267. Identity, personal, confusion of, in dreams, 163; consciousness of, 241, 267, 282, 285; illusory forms of, 283; gross disturbances of, in normal life, 287; in abnormal life, 289; momentary confusions of, 293. Illusion, definition of, 1; varieties of, 9; extent of, 328; _rationale_ of, 331, 337. Image (physical). _See_ Reflection. Image (mental), in perception, 22; seat of, 32; in dreams, 138; mnemonic, 236. Imagination, play of, in perception, 95, 99; and sense-illusion, 106; nature of, in dreaming, 136, 161; as antecedent of dream, 152, 158; as poetic interpretation of nature, 224; memory corrupted by effect of past, 264, 273, 277; present, creating the semblance of recollection, 267, 271; play of, in expectation, 305; as element of illusion generally, 333. Immediate. _See_ Cognition. Individual, and common experience, 26, 27, 137, 209, 214, 336; dream-experience as, 44, 68; internal experience as, 209; memory as, 232; belief and truth, 338. Inference, and immediate knowledge, 6, 334; in perception, 22, 26, 68; in belief, 295. Innate, recollection as, 280; principles, 295, 356.