CHAPTER X. 



CONSCIOUSNESS. 



Consciousness as a natural phenomenon. Its definition. Diffi- 

 culties of the problem. Its relation to the life of the soul. Our 

 human consciousness. Various theories : I. Anthropistic theory 

 (Descartes). II. Neurological theory (Darwin). III. Animal 

 theory (Schopenhauer). IV. Biological theory (Fechner). V. 

 Cellular theory (Fritz Schultze). VI. Atomistic theory. Monistic 

 and dualistic theories. Transcendental character of consciousness. 

 The Ignorabimus verdict of Du Bois-Reymond. Physiology of 

 consciousness. Discovery of the organs of thought by Flechsig. 

 Pathology. Double and intermittent consciousness. Ontogeny 

 of consciousness : modifications at different ages. Phylogeny of 

 consciousness. Formation of concepts. 



No phenomenon of the life of the soul is so wonderful 

 and so variously interpreted as consciousness. The 

 most contradictory views are current to-day, as they 

 were 2,000 years ago, not only with regard to the 

 nature of this psychic function and its relation to the 

 body, but even as to its diffusion in the organic world 

 and its origin and development. It is more respon- 

 sible than any other psychic faculty for the erroneous 

 idea of an " immaterial soul " and the belief in 

 " personal immortality " ; many of the gravest errors 

 that still dominate even our modern civilisation may 

 be traced to it. Hence it is that I have entitled 

 consciousness "the central mystery of psychology" : 

 it is the strong citadel of all mystic and dualistic 

 errors, before whose ramparts the best equipped 



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