Clifford, Professor W.K., 56, note[24].

  Coalescence, of sensations, 43, 52;
    of dream-images, 162;
    of internal feelings, 196;
    of mnemonic images, 265.

  Coenaesthesis, 41, 99, 145, 286, 288.

  Cognition, immediate or intuitive, 5, 14-16, 294;
    presentative and representative, 9, 13, 217, 330;
    nature of, in dreams, 168, 172;
    nature of, generally, 295, 331;
    philosophic problems of, 346.

  Colour, external reality of, 8, 37;
    illusory perception of, 37, 88;
    subjective complementary colours (colour-contrast), 67, 83.

  Coloured media, objects seen through, 82.

  Common cognition, and truth, 337;
    genesis and validity of, 353.

  Common experience distinguished from
    individual, 26, 27, 137, 209, 214, 336, 351;
    illusion as, 47,325, 337.

  Common sense, intuitions of, 346, 349, 352, 357.

  Complementary colours, 67, 83.

  Concave, apparent conversion of, into convex, 84.

  Conjuror, tricks of, 56, 106.

  Consciousness, veracity of, 192, 205;
    inspection of phenomena of, 196;
    of self, 283, 285.

  Consensus, the standard of truth, 7, 8, 211, 325, 338, 357.

  Conservation of energy, 343.

  Construction, rational, in dreams, 170.

  Continuum, the perception of the world as, 52, 56, note[24].

  Correction of illusion, in sense-illusion, 38, 124, 137;
    dreams, 182;
    introspection, 210;
    insight, 229;
    memory, 291;
    historical correction 338;
    intellectual processes involved in, 351.

  Criterion of illusion, 337.

  Cudworth, R., 161

  D.

  Deception of the senses, 19;
    self-deception, 200;
    conscious deception of others, 222.

  Delboeuf, J., 175, note[97], 235, note[113].

  Delirium tremens, 118, note[62].

  Democritus, 130.

  De Quincey, 253, 280.

  Descartes, R., 116, 350.

  Dickens, Charles, 277.

  Direction, illusory sense of, in vision, 66, 71, 73;
   in hearing, 72, 75.

  Disease. See Abnormal life.

  Dissolution. See Evolution.

  Doubt, starting-point in philosophy, 350.

  Dreams, relation of, to illusions of sense, 18, 130;
    and waking experience, 127;
    theories of, 128;
    physiology of, 131;
    extent of, in sleep, 132;
    psychological conditions of, 136;
    excitants of, 139, 143;
    exaggeration in, 147;
    symbolism of, 149;
    as results of automatic activity of centres, 151;
    as results of association, 153;
    structure of, 156;
    incoherent, 156;
    coherent, 161;
    action of feeling in, 164;
    play of associative dispositions