The Law of Continuity having been referred to already as a prominent factor in this inquiry, it may not be out of place to sustain the plea for Natural Law in the Spiritual Sphere by a brief statement and application of this great principle. The Law of Continuity furnishes an _a priori_ argument for the position we are attempting to establish of the most convincing kind--of such a kind, indeed, as to seem to our mind final. Briefly indicated, the ground taken up is this, that if Nature be a harmony, Man in all his relations--physical, mental, moral, and spiritual--falls to be included within its circle. It is altogether unlikely that man spiritual should be violently separated in all the conditions of growth, development, and life, from man physical. It is indeed difficult to conceive that one set of principles should guide the natural life, and these at a certain period--the very point where they are needed--suddenly give place to another set of principles altogether new and unrelated. Nature has never taught us to expect such a catastrophe. She has nowhere prepared us for it. And Man cannot in the nature of things, in the nature of thought, in the nature of language, be separated into two such incoherent halves.
The spiritual man, it is true, is to be studied in a different department of science from the natural man. But the harmony established by science is not a harmony within specific departments. It is the universe that is the harmony, the universe of which these are but parts. And the harmonies of the parts depend for all their weight and interest on the harmony of the whole. While, therefore, there are many harmonies, there is but one harmony. The breaking up of the phenomena of the universe into carefully guarded groups, and the allocation of certain prominent Laws to each, it must never be forgotten, and however much Nature lends herself to it, are artificial. We find an evolution in Botany, another in Geology, and another in Astronomy, and the effect is to lead one insensibly to look upon these as three distinct evolutions. But these sciences, of course, are mere departments created by ourselves to facilitate knowledge--reductions of Nature to the scale of our own intelligence. And we must beware of breaking up Nature except for this purpose. Science has so dissected everything, that it becomes a mental difficulty to put the puzzle together again; and we must keep ourselves in practice by constantly thinking of Nature as a whole, if science is not to be spoiled by its own refinements. Evolution being found in so many different sciences, the likelihood is that it is a universal principle. And there is no presumption whatever against this Law and many others being excluded from the domain of the spiritual life. On the other hand, there are very convincing reasons why the Natural Laws should be continuous through the Spiritual Sphere--not changed in any way to meet the new circumstances, but continuous as they stand.
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.