Our answer is that if we had been treating of Hume as a great literary character, or exhibiting the history of his individual mind, due account must have been taken of it. Such, however, has not been the object which, in the Introductions to Volumes I. and II., we have presented to ourselves, (See Introd. to Vol. I. § 4.) Our concern has been with him as the exponent of a philosophical system, and therefore specially with that statement of his system which alone purports to be complete, and which was written when philosophy was still his chief interest, without alloy from the disappointment of literary ambition. Anyone who will be at the pains to read the ‘Inquiries’ alongside of the original ‘Treatise’ will find that their only essential difference from it is in the way of omission. They consist in the main of excerpts from the ‘Treatise,’ re-written in a lighter style, and with the more difficult parts of it left out. It is not that the difficulties which logically arise out of Hume’s system are met, but that the passages which most obviously suggest them have disappeared without anything to take their place. Thus in the ‘Inquiry concerning the Human Understanding’ there is nothing whatever corresponding to Parts II. and IV. of the first Book of the ‘Treatise.’ The effect of this omission on a hasty reader is, no doubt, a feeling of great relief. Common-sense is no longer actively repelled by a doctrine which seems to undermine the real world, and can more easily put a construction on the account of the law of causation, which remains, compatible with the ‘objective validity’ of the law--such a construction as in fact forms the basis of Mr. Mill’s Logic. How inconsistent this construction is with the principles from which Hume started, and which he never gave up; how impossible it would be to anyone who had assimilated his system as a whole; how close is the organic connection between all the parts of this as he originally conceived it--we must trust to the following introductions to show. (See, in particular, Introd. to Vol. I. §§ 301 and 321.) The only discussion in the ‘Inquiry concerning Human Understanding,’ to which nothing in his earlier publication corresponds, is that on Miracles. On the relation in which this stands to his general theory some remarks will be found in the Introduction to Vol. I. (§ 324, note). The chief variations, other than in the way of omission, between the later redaction of his ethical doctrine and the earlier, are noticed in the Introduction to Vol. II. (§§ 31, 43, and 46, and notes). SUMMARY OF THE CONTENTS of the GENERAL INTRODUCTION TO VOL. I 1. How the history of philosophy should be studied. 2. Hume the last great English philosopher. 3. Kant his true successor. 4. Distinction between literary history and the history of philosophical systems. 5. Object of the present enquiry. 6. Locke’s problem and method. 7. His notion of the ‘thinking thing’. 8. This he will passively observe.