Spiritualist view that death cuts link between soul and body--Explanation of link fatal to system--Consciousness cannot exercise functions without objects of cognition--Idealism a kaleidoscopic system--Four affirmations of idealism: their inconsistency--Advantages of historical method CHAPTER III MATERIALISM AND PARALLELISM Materialism oldest doctrine of all: many patristic authors lean towards it--Modern form of, receives impulse from advance of physical science--Karl Vogt's comparison of secretions of brain with that of kidneys--All materialist doctrines opposed to principle of heterogeneity--Modern materialism would make object generate consciousness--Materialists cannot demonstrate how molecular vibrations can be transformed into objects--Parallelism avoids issue by declaring mind to be function of brain--Parallelists declare physical and psychical life to be two parallel currents--Bain's support of this--Objections to: most important that it postulates consciousness as a complete whole CHAPTER IV MODERN THEORIES Berkeley's idealism revived by Bergson, though with different standpoint--Admirable nature of Bergson's exposition--Fallacy of, part assigned to sensory nerves--Conscious sensations must be subsequent to excitement of sensory nerves and dependent on their integrity CHAPTER V CONCLUSION Author's own theory only a hypothesis--Important conditions for solution of problem--Manifestations of consciousness conditioned by brain, but this last unconscious--Consciousness perceives only external object--Specificity of nerves not absolute--Why repeated excitements of nerve tend to become unconscious--Formation of habit and "instinct"--Resemblance to and distinction of this from parallelism--Advantages of new theory CHAPTER VI RECAPITULATION Description of matter--Definition of mind--Objections to, answered--Incomplete existence of mind--Other theories--Nervous system must add its own effect to that of its excitant BOOK I THE DEFINITION OF MATTER THE MIND AND THE BRAIN[1] CHAPTER I INTRODUCTION This book is a prolonged effort to establish a distinction between what is called mind and what is called matter. Nothing is more simple than to realise this distinction when you do not go deeply into it; nothing is more difficult when you analyse it a little. At first sight, it seems impossible to confuse things so far apart as a thought and a block of stone; but on reflection this great contrast vanishes, and other differences have to be sought which are less apparent and of which one has not hitherto dreamed.