TO MY DEAR FRIEND FRANÇOIS PILLON. AS A TOKEN OF AFFECTION, AND AN ACKNOWLEDGMENT OF WHAT I OWE TO THE CRITIQUE PHILOSOPHIQUE. The treatise which follows has in the main grown up in connection with the author's class-room instruction in Psychology, although it is true that some of the chapters are more 'metaphysical,' and others fuller of detail, than is suitable for students who are going over the subject for the first time. The consequence of this is that, in spite of the exclusion of the impo

Psychology is the Science of Mental Life, both of its phenomena and of their conditions. The phenomena are such things as we call feelings, desires, cognitions, reasonings, decisions, and the like; and, superficially considered, their variety and complexity is such as to leave a chaotic impression on the observer. The most natural and consequently the earliest way of unifying the material was, first, to classify it as well as might be, and, secondly, to affiliate the diverse mental modes thus fo

CHAPTER XVII. Sensation , 1 Its distinction from perception, 1 . Its cognitive function—acquaintance with qualities, 3 . No pure sensations after the first days of life, 7 . The 'relativity of knowledge,' 9 . The law of contrast, 13 . The psychological and the physiological theories of it, 17 . Hering's experiments, 20 . The 'eccentric projection' of sensations, 31 . CHAPTER XVIII. Imagination , 44 Our images are usually vague, 45 . Vague images not necessarily general notions, 48 . Individuals

After inner perception, outer perception! The next three chapters will treat of the processes by which we cognize at all times the present world of space and the material things which it contains. And first, of the process called Sensation. The words Sensation and Perception do not carry very definitely discriminated meanings in popular speech, and in Psychology also their meanings run into each other. Both of them name processes in which we cognize an objective world; both (under normal conditi