definition and explanation which implies this idea. He says: "Taking tins view of illusion, we may provisionally define it as any species of error which counterfeits the form of immediate, self-evident, or intuitive knowledge, whether as sense-perception or otherwise. Whenever a thing is believed on its own evidence and not as a conclusion from something else, and the thing then believed is demonstrably wrong, there is an illusion. The term would thus appear to cover all varieties of error which are not recognized as fallacies or false inferences. If for the present we roughly divide all our knowledge into the two regions of primary or intuitive, and secondary or inferential knowledge, we see that illusion is false or spurious knowledge of the first kind, fallacy false or spurious knowledge of the second kind. At the same time, it is to be remembered that this division is only a very rough one. As will appear in the course of our investigation, the same error may be called either a fallacy or an illusion, according as we are thinking of its original mode of production or of the form which it finally assumes; and a thorough-going psychological analysis of error may discover that these two classes are at bottom very similar."

It will be obvious that this is not a technical work, but one of wide popular interest, in the principles and results of which every one is concerned. The illusions of perception of the senses and of dreams are first considered, and then the author passes to the illusions of introspection, errors of insight, illusions of memory, and illusions of belief. The work is a noteworthy contribution to the original progress of thought, and may be relied upon as representing the present state of knowledge on the important subject to which it is devoted.

A most readable volume, full of common sense and practical wisdom on a great number of important and interesting subjects. The author is evidently an omnivorous and careful reader, and has well cultivated the art of turning his varied studies to good literary account. His pages are loaded, we might almost say overloaded, with references to the best writers, and quotations of their trenchant and suggestive sayings. The first paper, on "Literary Style," from which the volume takes its name, is not a scientific or philosophical analysis of the subject, but is a formidable array of arguments, illustrations, and authorities to prove that literary form is the main thing in the art of authorship. Dr. Mathews shows that, in literature, ideas, facts, and the substance of thought go for next to nothing, while the style of verbal dress determines the place and permanence of literary productions. The following passage on Carlyle will exemplify the fundamental idea of the essay, and illustrate also the author's lively and earnest style of discussion: