the most vigorous as well as boldest thinkers that English speculation has yet produced, full of the true scientific spirit, Mr Herbert Spencer, places in the front of his philosophy the doctrine that the ultimate test of the truth of a proposition is the inconceivableness of its negative; when, following in the steps of Mr Spencer, an able expounder of positive philosophy like Mr Lewes, in his meritorious and by no means superficial work on Aristotle, after laying, very justly, the blame of almost every error of the ancient thinkers on their neglecting to _verify_ their opinions, announces that there are two kinds of verification, the Real and the Ideal, the ideal test of truth being that its negative is unthinkable, and by the application of that test judges that gravitation must be universal even in the stellar regions, because in the absence of proof to the contrary, "the idea of matter without gravity is unthinkable;"--when those from whom it was least to be expected thus set up acquired necessities of thought in the minds of one or two generations as evidence of real necessities in the universe, we must admit that the metaphysical mode of thought still rules the higher philosophy, even in the department of inorganic nature, and far more in all that relates to man as a moral, intellectual, and social being. But, while M. Comte is so far in the right, we often, as already intimated, find him using the name metaphysical to denote certain practical conclusions, instead of a particular kind of theoretical premises. Whatever goes by the different names of the revolutionary, the radical, the democratic, the liberal, the free-thinking, the sceptical, or the negative and critical school or party in religion, politics, or philosophy, all passes with him under the designation of metaphysical, and whatever he has to say about it forms part of his description of the metaphysical school of social science. He passes in review, one after another, what he deems the leading doctrines of the revolutionary school of politics, and dismisses them all as mere instruments of attack upon the old social system, with no permanent validity as social truth.