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PREFACE TO THE SECOND EDITION.

knowledge, and is more particularly suited for those who are entering on the study of Mental Philosophy. It traces the history of the Science of Reasoning from the earliest period to the present time; it unfolds its fundamental principles and rules, accompanied with appropriate illustrations; and points out, at considerable length, its application to practical purposes. The limits of the work rendered it necessary that brevity should be, as much as possible, studied. It is hoped, however, that nothing really essential to the subject has been overlooked.

In compiling this work, the Author has availed himself most freely of the labours of his predecessors. He has consulted several Compendiums of Aristotle's Logic, which are used as Class-Books in the Universities of Europe. He has taken without scruple from the works of Bacon, Campbell, Reid, Stewart, Jardine, Duncan, and other writers on Logic and Mental Science, whatever appeared most suitable to his purpose. To the admirable work of Dr Whately, he acknowledges, in a particular manner, his obligations. The Author begs leave gratefully to record the very courteous manner in which, in preparing this Second Edition for the press, the Archbishop has permitted him to make the freest use of his Grace's invaluable labours. He has, therefore, most gladly availed himself of this generous permission. This has been the case particularly in the Chapter on Fallacies, which the Archbishop has discussed with uncommon ability.

When turning to profit the help of others, the Author

has thought it unnecessary to point out, in every instance, the sources whence he has derived his information. In many cases this would have been impossible, as the truths brought forward have been so long familiar to the mind, that the sources whence they were originally derived have been forgotten. In any case to have brought forward authorities would have been of no service. What has once been communicated to the world has become public property; and it is only with regard to new or debatable opinions in literary and scientific matters that authorities are of any value. The language of an able writer, in reference to another department of science, may be applied to the subject now before us: "The advanced state of a science is but the accumulation of the discoveries and inventions of many; to refer each of these to its author is the business of the history of the science, but does not belong to a work which professes merely to give an account of the science as it is; all that is generally acknowledged must pass current from author to author.”*

This Second Edition has been carefully revised, and considerably enlarged;—it is hoped it may furnish such an Introduction to this study as has hitherto been wanting.

*Brett's "Principles of Astronomy," p. v.

IRVINE, 14th October 1844.

ADVERTISEMENT TO THE THIRD EDITION.

As proficiency in the study of Logic can scarcely be attained without a practical acquaintance with its rules, there has been added in this Edition, besides numerous Miscellaneous Examples for practice, a Progressive Series of Exercises, embracing all the important parts of the subject. This addition, the Author ventures to hope, will render the work still more suitable for our higher Seminaries of learning, as well as for those who may wish to prosecute the study in private.

November 1846.