meaning, leading to endless confusion and misunderstanding. Psychologists themselves deplore the ambiguities of the word "consciousness." "There is no philosophical term at once so popular and so devoid of standard meaning. How can a term mean anything when it is employed to connote anything and everjrthing, including its own negation?"[1] "For the sake of clearness, terms like mind and psychosis will be substituted for 'consciousness,' owing to its ambiguity."[2] Of consciousness Avenarius says, "It would be better to give up entirely so treacherous a term."[3]
In the following illustrations of the emphasis placed upon consciousness in recent science, it should be remembered, then, that the word is used either as quite synonymous with the older words "mind" and "soul," or else, as is quite commonly the case, it is used in the sense of an indefinite, not wholly known, psychic factor of life and progress. In this latter sense the word soul, if it were permitted to use it, would be still more appropriate. The careful reader in contemporary psychological and biological science will make the further interesting discovery that the word "consciousness" is also used in the original and more proper sense, as subject-object consciousness or self-consciousness, and that it is usually so used by those writers who are engaged in showing that consciousness is an evolutionary product of life and organization, while, on the other hand, those now numerous writers and investigators who believe that consciousness is a primitive datum or deep underlying force of life, organization and progress, use the word in one of the other two senses just mentioned.
Let us take, then, a few illustrations of the emphasis which recent science is putting upon consciousness as a world factor of primary importance. Let it be borne in mind that until recently there were few outside the ranks of idealistic philosophers to dispute the prevalent belief that mechanical laws are sufficient to account for every phase of human life, including mental and moral phenomena; that at certain stages of organic evolution consciousness appears as a kind of byproduct and has no agency in the life drama itself, and that it is not necessary to take any causal account of it in explaining life in its physiological, psychological or social aspects. With this view compare that of many representative present-day psychologists who hold that consciousness, although itself perhaps a product of evolution, has become a factor in evolution of the very first importance, changing not only the very face of the earth, but changing the direction of evolution itself. One writer says:
