The Principles of Psychology, Volume 2 (of 2)

function--acquaintance with qualities. No pure sensations after the first days of life. The 'relativity of knowledge'. The law of contrast. The psychological and the physiological theories of it. Hering's experiments. The 'eccentric projection' of sensations. CHAPTER XVIII. IMAGINATION Our images are usually vague. Vague images not necessarily general notions. Individuals differ in imagination; Gabon's researches. The 'visile' type, 58. The 'audile' type. The 'motile' type. Tactile images, 65. The neural process of imagination. Its relations to that of sensation. CHAPTER XIX. THE PERCEPTION OF 'THINGS' Perception and sensation. Perception is of definite and probable things. Illusions;--of the first type;--of the second type. The neural process in perception. 'Apperception'. Is perception an unconscious inference? Hallucinations, 114. The neural process in hallucination. Binet's theory. 'Perception-time'. CHAPTER XX. THE PERCEPTION OF SPACE CHAPTER XX. THE PERCEPTION OF SPACE The feeling of crude extensity. The perception of spatial order. Space-'relations'. The meaning of localization. 'Local signs'. The construction of 'real' space. The subdivision of the original sense-spaces. The sensation of motion over surfaces. The measurement of the sense-spaces by each other. Their summation. Feelings of movement in joints. Feelings of muscular contraction. Summary so far. How the blind perceive space. Visual space. Helmholtz and Reid on the test of a sensation. The theory of identical points. The theory of projection. Ambiguity of retinal impressions;--of eye-movements. The choice of the visual reality. Sensations which we ignore. Sensations which seem suppressed.…