Mill, in the 'Essay on Liberty,' declares war as champion of Reasoned Truth. He handles this grand theme--_eleythheroys eleythherôs philosophein_--involving as it does the best interests of philosophy, as an instructress to men's judgments, and a stimulus to their intelligence--with great depth of psychological analysis sustained by abundant historical illustration. And he in the same volume discusses most profitably another question akin to it--To what extent, and by what principles, the interference of others is justifiable, in restraining the liberty of taste and action for each individual? A question at once grave and neglected, but the discussion of which does not belong to our present article. A new work from one who has already manifested such mastery of philosophy, both in principle and in detail, and a work exhibiting the analysis and appreciation of the philosophical views of an eminent contemporary, must raise the highest expectation. We think no reader will be disappointed who peruses Mr Mill's 'Examination,' and we shall now endeavour to give some account of the manner in which he performs it. Upon topics so abstract and subtle as the contents of this volume, the antithesis between two rival theories is the best way, and often the only way, for bringing truth into clear view; and the 'Examination' here before us is professedly controversy. But of controversy in its objectionable sense--of captious or acrimonious personality--not a trace will here be found. A dignified, judicial equanimity of tone is preserved from first to last. Moreover, though the title and direct purpose of the volume is negative and critical, yet the destructive criticism is pervaded by many copious veins of constructive exposition, embodying Mr Mill's own views upon some of the most intricate problems of metaphysics. Mr Mill begins his work by analyzing and explaining the doctrine called the Relativity of Human Knowledge: 'The doctrine (chap. ii. p. 5) which is thought to belong in the most especial manner to Sir W. Hamilton, and which was the ground of his opposition to the transcendentalism of the later French and German metaphysicians, is that which he and others have called the Relativity of Human Knowledge. It is the subject of the most generally known and impressive of all his writings--the one which first revealed to the English metaphysical reader that a new power had arisen in philosophy. Together with its developments, it composes the Philosophy of the Conditioned, which he opposed to the French and German philosophies of the Absolute, and which is regarded by most of his admirers as the greatest of his titles to a permanent place in the history of metaphysical thought. But, "the relativity of human knowledge," like most other phrases into which the words _relative_ or _relation_ enter, is vague, and admits of a great variety of meanings,' &c.