The most fierce and fiery discussions on theological matters resolve themselves into disputes about words is a commonplace; but such a work as this anew proves that the same to a very great extent applies in philosophy. Men differ as they do, largely because they use terms differently, and refuse to look patiently from each other's point of view. Mr. F. Harrison warmly insists, for example, that there is no need for Comtists to spell humanity with a big H, however enthusiastic they may be; while his opponents triumphantly insist that to be consistent they must do so; and Sir James Stephen refuses to regard this assertion as aught but nonsense. One cannot regard the writings of Lucretius, or the theory of atoms which he propounded, without being at once pulled up in front of the question, What is matter? and the somewhat warm replies of modern philosophers do not tend to make matters easier. Yet here lies the whole gist of the subject. Mr. Masson is not ambitious enough to aim at an exhaustive definition on his own account, but he points out with no little discrimination the defects in the definitions of Professors Huxley and Tyndall, and other writers of our day, as well as in the conclusions of thinkers like Mr. Picton; and he deserves all praise for the careful and thoughtful style in which he has analyzed the doctrines of the Epicurean philosophy, and more especially-as he was in duty bound to do-the doctrines of Lucretius. He shows in the clearest manner that Lucretius - pace Mr. Robert Buchanan and those who lead or follow him-was no cut and dry materialist, but something so different that he may well be regarded as the teacher of ideas in effect identical with those which are in our own day revolutionizing science and philosophy. Lucretius held, in reality, something in common with the 'mind-stuff of Professor Clifford, for if he persists in regarding matter as dead, his theory of atoms includes soul-atoms, in some of which volition is vested; and in these are logically found the bases for free-will, which no mere materialist could assert. Will, with Lucretius, is held so to act on matter that Mr. Masson ingenuously writes: "Lucretius' conception of Declination as a movement so exceedingly slight, the tiny soul-atom swerving from the straight line "not more than the least possible" degree at the impulse of its own Freewill-does not this come pretty near to Herschel's "no greater force than is required to remove a single material molecule from its place through a space inconceivably minute" (p. 117)? This, which seems formally mechanical, is in reality moral. Of course Mr. Masson dwells, as he could not help doing, on the grand lacuna in the philosophy of Lucretius-his total failure to account for consciousness. Lucretius admitted no more than sensation, which he holds is felt in the body as a whole, and not in any part separately, and yet he insisted on the sense of free-will. But Mr. Masson has made it clear that Lucretius, if he did not clearly formulate all his conceptions, perceived the necessity of founding on personal experience; and if he did not see his way to accept the immortality of the soul, this was a defect, for the principle of free-will logically implied it. One of the happiest summaries of the points of relationship between Lucretius and Professor Clifford and his school of thinkers is thus given by Mr. Masson: 'The reasoning of both is based on the same principle, and both apply it with equal boldness. The question is an instructive one. In both cases materialism, finding itself hard pressed, escapes as it were by a back-door, and, in so doing, unconsciously confesses its own powerlessness to account, unaided, for the origin of life and thought. In one point the pagan has the advantage of the modern philosophy, in showing none of the bitterness against all forms of religious belief.... -The British Quarterly Review, Volume 80 [1884]