Practically, however, Comte regards gravitation as a force. The order of the solar system has been established and is still maintained by the mutual gravity of its several parts. We shall not stop here to note the inconsistency of his denying to us the knowledge of, even the existence of, force, and yet at the same time assuming to treat gravitation as a force really adequate to the explanation of the _how_ and _why_ of the phenomena of the universe, without any reference to a supernatural will or an intelligent mind. The question with which we are immediately concerned is whether gravitation _alone_ is adequate to the explanation of the phenomena of the heavens? A review _in extenso_ of Comte's answer to this question would lead us into all the inextricable mazes of the nebular hypothesis, and involve us in a more extended discussion than our space permits and our limited scientific knowledge justifies. For the masses of the people the whole question of cosmical development resolves itself into "a balancing of authorities;" they are not in a position to verify the reasonings for and against this theory by actual observation of astral phenomena, and the application of mathematical calculus; they are, therefore, guided by balancing in their own minds the statements of the distinguished astronomers who, by the united suffrages of the scientific world, are regarded as "authorities." For us, at present, it is enough that the nebular hypothesis is rejected by some of the greatest astronomers that have lived. We need only mention the names of Sir William Herschel, Sir John Herschel, Prof. Nichol, Earl Rosse, Sir David Brewster, and Prof. Whewell.