But to the exposition. One of the most striking generalizations of recent science is that even Laws have their Law. Phenomena first, in the progress of knowledge, were grouped together, and Nature shortly presented the spectacle of a cosmos, the lines of beauty being the great Natural Laws. So long, however, as these Laws were merely great lines running through Nature, so long as they remained isolated from one another, the system of Nature was still incomplete. The principle which sought Law among phenomena had to go further and seek a Law among the Laws. Laws themselves accordingly came to be treated as they treated phenomena, and found themselves finally grouped in a still narrower circle. That inmost circle is governed by one great Law, the Law of Continuity. It is the Law for Laws. It is perhaps significant that few exact definitions of Continuity are to be found. Even in Sir W. R. Grove's famous paper,[21] the fountain-head of the modern form of this far from modern truth, there is no attempt at definition. In point of fact, its sweep is so magnificent, it appeals so much more to the imagination than to the reason, that men have preferred to exhibit rather than to define it. Its true greatness consists in the final impression it leaves on the mind with regard to the uniformity of Nature. For it was reserved for the Law of Continuity to put the finishing touch to the harmony of the universe. Probably the most satisfactory way to secure for one's self a just appreciation of the Principle of Continuity is to try to conceive the universe without it. The opposite of a continuous universe would be a discontinuous universe, an incoherent and irrelevant universe--as irrelevant in all its ways of doing things as an irrelevant person. In effect, to withdraw Continuity from the universe would be the same as to withdraw reason from an individual. The universe would run deranged; the world would be a mad world.