Object, nature of, 36, 353.

  Objective and subjective experience, 26, 27, 137, 214.

  Old age, dreams how regarded in, 276.

  Oneirocritics, 129.

  Opera, illusion connected with, 104.

  Optimism, 323, 327, 342.

  Organic sensations, discrimination of, 41;
    interpretation of, 99;
    in sleep, 145, 148.

  Organism, conditions of illusion in, 47, 50;
    relation of our conception of the universe to sensibilities of, 343.

  Orientation, 125, 138.

  P.

  Pain, recollection of, 264, 270.

  Painting, representation of third dimension by, 77;
    apparent movement of eye in portrait, 81;
    discrepancies between, and object in magnitude and luminosity, 88;
    realization of, and mental preparation, 105;
    realization of, by animals, 105.

  Paraesthesia, 68.

  Paralysis of ocular muscles, 66.

  Passive, and active factor in perception, 27;
    and active illusion, 45.

  Percept, 22;
    and sense-impression, 59.

  Perception, a form of immediate knowledge, 10, 13, 17, 18;
    external and internal, 14;
    philosophy of, 14, 20, 22, 36, 346, 348, 353, 355, 359;
    illusions of, 19, 35;
    psychology of, 20;
    and inference, 22, 26, 76;
    physiological conditions of, 31.

  Persistent objects, representation of, 312.

  Persistent self. See Personal identity.

  Personal equation, in perception, 101;
    in aesthetic intuition, 214;
    in memory, 292;
    in belief, 324.

  Personal identity, consciousness of, 241, 282, 285;
    illusions connected with, 283;
    disturbances in sense of, 287;
    sense of, in insanity, 289;
    momentary confusions of, 293;
    philosophic problem of, 285, 354, 360.

  Personification of nature, 224.

  Perspective, linear, 79, 97, 98;
    aerial, 80;
    of memory, 245.

  Pessimism, 323, 327.

  Phenomenalism, 348.

  Philosophy, conception of illusion by, 7, 36, 205, 285, 349;
    of mind, 132, 285, 344, 348;
    as theory of knowledge, 295, 346;
    and science, 346, 348;
    and common sense, 347, 349;
    problems of, 347.

  Phosphenes, 58.

  Physical science. See Science.

  Plato, 281.

  Platonists, 349.

  Pleasure, feeling of, 200;
    recollection of, 264, 270.

  Plutarch, 133, note[73].

  Poetry, lyrical and dreams, 164;
    misinterpretation of, 223;
    personification, 224.

  Points, discrimination of, 52.

  Poisons, action of, 115.

  Pollock, F., 184, note[101].

  Pollock, W.H., 184.

  Predisposition, action of, in perception, 44, 101, 102;
    in aesthetic intuition, 215;
    in insight, 223;
    in recollection, 268;
    in belief, 305, 319;
    belief as, 324.