About one-fourth of this volume was published some months since, in a small spirited Irish periodical. It is now given to the public not only enlarged in matter, but also altered in form. I am not so contracted in View, and vain in expecta tion, as to think that it will settle the vexed question between the realist and the idealist. If it will in any way advance knowledge, and cast a ray of light on any dark spot on the canvass of human vision, it will satisfy my expectation and wish. The book is not intended for the advanced and the erudite; but for those who aspire after advancement and knowledge, and receive with gratitude any light and assistance, from whatever quarter they may come. The intent is, to give within a narrow compass, some acquaintance with Berkeley's theory, to those who have not studied his works for themselves it aims also to help and encourage the student of metaphysical science, in his lonely and persevering efforts.