be, however, its organs as Lewes defined them, but rather, from a positive standpoint, the ultimate units recognized by science in cell and cell-parts. We may, indeed, since we know no beginning of motion, legitimately regard all tendency as itself resultant. Just as we cannot separate matter and motion, except by abstraction from reality, so, too, we cannot conceive of motion except as having definite direction; and thus we arrive, by a final analysis, at the ultimate philosophic principles of matter and its motion. I use these terms in no metaphysical sense, but merely as generic terms including under one head specific forms of material combination and the specific forms of motion of their wholes or parts. The question of the character of a conceived state of final equilibrium may be approached from a somewhat different side, though the emphasis falls, as before, on the solidarity of the universe and the nature of motion as change. We may, for instance, regard the earth as an isolated system whose isolation makes possible the continual progress of the evolution taking place on its surface. But this whole evolution is, on the other hand, dependent upon the light and heat of the sun. Again, the sun is undergoing an evolution whose continuous progress may be regarded as in a certain sense dependent upon isolation; but we see, on reflection, that this very process is the result of the cooling nature of the sun's surroundings, and that it is sending its motion in every direction through space. The moon, which has passed through both the evolution that the sun is undergoing and that which is in progress upon the earth, is now passing through another stage which the earth must reach in time by diffusion of its atmosphere, in case its destruction is not accomplished by some catastrophic event before the arrival of that distant period. Suns and planets, all the heavenly bodies, are sending their influence in every direction through the unfathomable depths of space; and just as the capacity of the earth to be warmed by the influence of the sun involves its reciprocal capacity to act as a cooling medium for that body, so the conditions throughout the universe must be regarded as everywhere interdependent and mutually implying one another. Thus we again arrive finally at a universal action and reaction among the parts of the universe, all motion implying change of the direction of motion. Or, since we may and are, in fact, obliged to regard every direction or form of motion as a resultant,--for of motion as of matter we know no absolute beginning,--even this simple assumption may supply us with the conclusion which we have reached in a more roundabout way. We may regard motion in any direction as counterbalanced by a resistance in every other direction sufficient to produce it in this one; in other words, motion takes place at every instant, in the direction of least resistance, even though this direction may represent,