In this edition the author has corrected the style throughout, simplified the arrangement in some places, added a few more illustrative facts in the Physical portion, and given a fuller exposition of his views of First Principles. But the most important alteration consists in transferring to an Appendix the discussions on Fundamental Principles, so far as they are not necessary to the consecutiveness of the argument in the text. In this way, he trusts that he has made the body of the work clearer and more interesting to the general reader, while the student with a taste for abstract philosophy will find the metaphysical disquisitions in a more connected form in the Appendix.

In issuing the former edition, the author was not a little afraid that a work on such a subject by an unknown author might fail to secure any attention. The deepest feeling which he cherishes, on being called so speedily to issue a second edition, is that of gratitude to the God of Providence, who has been pleased to open up a favourable reception for his volume, and to the Public Press, which, with scarcely an exception, has given it a welcome beyond its merits.