chapter I

have used the term in a broader sense, for both the

materialist and the spiritualist maintain that there is in the universe but one kind of thing. Nevertheless, when we hear a man called a monist without qualification, we may, perhaps, be justified in assuming, in the absence of further information, that he holds to some one of the forms of doctrine indicated above. There may be no logical justification for thus narrowing the use of the term, but logical justification goes for little in such matters.

Various considerations have moved men to become monists in this sense of the word. Some have been influenced by the assumption--one which men felt impelled to make early in the history of speculative thought--that the whole universe must be the expression of some unitary principle. A rather different argument is well illustrated in the writings of Professor Höffding, a learned and acute writer of our own time. It has influenced so many that it is worth while to delay upon it.

Professor Höffding holds that mental phenomena and physical phenomena must be regarded as parallel (see