When this book had been already completed, I found, in Brentano’s ‘Origin of the Knowledge of Right and Wrong[1],’ opinions far more closely resembling my own, than those of any other ethical writer with whom I am acquainted. Brentano appears to agree with me completely (1) in regarding all ethical propositions as defined by the fact that they predicate a single unique objective concept; (2) in dividing such propositions sharply into the same two kinds; (3) in holding that the first kind are incapable of proof; and (4) with regard to the kind of evidence which is necessary and relevant to the proof of the second kind. But he regards the fundamental ethical concept as being, not the simple one which I denote by ‘good,’ but the complex one which I have taken to define ‘beautiful’; and he does not recognise, but even denies by implication, the principle which I have called _the principle of organic unities_. In consequence of these two differences, his conclusions as to what things are good in themselves, also differ very materially from mine. He agrees, however, that there are many different goods, and that the love of good and beautiful objects constitutes an important class among them. [1] ‘The Origin of the Knowledge of Right and Wrong.’ By Franz Brentano. English Translation by Cecil Hague. Constable, 1902.--I have written a review of this book, which will, I hope, appear in the _International Journal of Ethics_ for October, 1903. I may refer to this review for a fuller account of my reasons for disagreeing with Brentano. I wish to refer to one oversight, of which I became aware only when it was too late to correct it, and which may, I am afraid, cause unnecessary trouble to some readers. I have omitted to discuss directly the mutual relations of the several different notions, which are all expressed by the word ‘end.’ The consequences of this omission may perhaps be partially avoided by a reference to my article on ‘Teleology’ in Baldwin’s _Dictionary of Philosophy and Psychology_. If I were to rewrite my work now, I should make a very different, and I believe that I could make a much better book. But it may be doubted whether, in attempting to satisfy myself, I might not merely render more obscure the ideas which I am most anxious to convey, without a corresponding gain in completeness and accuracy. However that may be, my belief that to publish the book as it stands was probably the best thing I could do, does not prevent me from being painfully aware that it is full of defects. TRINITY COLLEGE, CAMBRIDGE. _August_, 1903.