The greater part, however, of the new matter in this edition is merely explanatory and supplementary. I have endeavoured to give a fuller and clearer account of my views on any points on which I either have myself seen them to be ambiguously or inadequately expressed, or have found by experience that they were liable to be misunderstood. Thus in Book i. chap. ii. I have tried to furnish a rather more instructive account than my first edition contained of the mutual relations of Ethics and Politics. Again, even before the appearance of Mr. Leslie Stephen’s interesting review in _Fraser_ (March 1875), I had seen the desirability of explaining further my general view of the ‘Practical Reason,’ and of the fundamental notion signified by the terms ‘right,’ ‘ought,’ etc. With this object I have entirely rewritten chap. iii. of Book i., and made considerable changes in chap. i. Elsewhere, as in chaps. vi. and ix. of Book i., and chap. vi. of Book ii., I have altered chiefly in order to make my expositions more clear and symmetrical. This is partly the case with the considerable changes that I have made in the first three chapters of Book iii.; but I have also tried to obviate the objections brought by Professor Calderwood[3] against the first of these chapters. The main part of this Book (chaps. iv.-xii.) has been but slightly altered; but in chap. xiii. (on ‘Philosophical Intuitionism’), which has been suggestively criticised by more than one writer, I have thought it expedient to give a more direct statement of my own opinions; instead of confining myself (as I did in the first edition) to comments on those of other moralists. Chap. xiv. again has been considerably modified; chiefly in order to introduce into it the substance of certain portions of an article on ‘Hedonism and Ultimate Good,’ which I published in _Mind_ (No. 5). In Book iv. the changes (besides those above mentioned) have been inconsiderable; and have been chiefly made in order to remove a misconception which I shall presently notice, as to my general attitude towards the three Methods which I am principally occupied in examining.