The World as Dynamical and Immaterial; and the Nature of
Perception. By R. S. Wyld. (Edinburgh: Oliver and Boyd.)—For a philosopher Mr. Wyld writes with remarkable clearness, and those who have entered at all into the questions with which he deals will find no difficulty in 'following his argument. But it is necessary for a right comprehension .of his book that they should have opened other books on the same subject, and should know something of the idealist and materialist theories which Mr. Wyld attempts to refute. Otherwise they will think that he is labouring to prove what is obvious, and that he contradicts what is still more obvious. The physical, philosophical, and common- sense arguments against the existence of matter which occupy much of his book will prove perplexing enough to the uninitiated, and all the more perplexing that even the uninitiated might understand the language in which these arguments are conveyed.