JAMES WARD, Naturalism and Agnosticism. 245 thinkers are fond of presenting to us as the demonstrated and established teaching of " science " about the constitution of the universe and our own position in it. As a critic of these " scien- tific " assumptions Dr. Ward has this advantage over Mr. Bradley, that the plan of his work enables him to deal with them in a concrete way and with a wealth of illustration much more readily apprehensible to the general reader and even to the average student of philosophy, than the profound but difficult and ab- stract argumentation of Appearance and Reality. There are three main classes of students to whom Naturalism and Agnosticism ought particularly to appeal. In the first place, the " natural theologians " ought to be specially grateful to Prof. Ward. Spiritualistic monism does not perhaps necessarily lead on to theism, but it is at least certain, as Prof. Ward shows, that materialistic monism and agnostic monism exclude any genuine theism, hence so powerful a defence of the spiritualist position and so telling a criticism of the popular agnosticism should con- tinue for years to furnish the more intelligent defenders of theistic beliefs with their most effective weapons of controversy. In the second place, Prof. Ward's exposure of the fallacies of dualism and of naturalistic or agnostic monism is so thorough and search- ing, that it may fairly be said any future exponent of a non-idealist philosophical system will be bound to take account of it and answer it, on pain of being condemned in advance. And in the third place, idealists of all shades of philosophic belief cannot but welcome most heartily so accomplished and fearless a champion of their common cause. Idealism is, of course, a word of somewhat un- certain meaning, and between those idealists who, like Prof. Ward, stand closest to Leibnitz and Lotze, and those who stand closest to Hegel there are important differences, which are not all differences of detail. Yet all who are agreed on the main principle that it is in mind, and nowhere else, that we are face to face with the central reality of the universe, must, whatever their disagree- ments among themselves, feel directly concerned in the success of so direct and trenchant an attack on the common foe. It is not so much the inherent difficulties of a spiritualist conception of the world that stand in the way of the general acceptance of Idealism, as its supposed inconsistency with certain supposedly established scientific generalisations about the constancy of the world's mass and energy and the universal reign of mechanical laws. It is by a direct examination of these supposed scientific principles and of the evidence for them, such as is conducted in these Gifford Lectures, that the cause of idealism can at the present moment be most effectively served ; by-and-by, when the main principle of idealistic philosophy has been successfully vindi- cated, and the nugatory character of the " scientific " objections against it satisfactorily exposed, it will be time for the disciples of Leibnitz and of Berkeley, of Lotze and of Hegel, to adjust their internal disputes. And it is because, as I have already said,