obtain otherness out of unity, but to gather the differences into a unity. An abstract unity will not suffice. It is not enough to abstract from the difference of each separate set of molecules, and generalise them all under the common name of matter; nor to abstract from the various energies at work in the universe, and generalise them under the common name of force: what is needed is a kind of unity which shall keep the differences, and recognise the special nature of each kind. And this is a unity made up of relations. Thus at the very basis of the material system there is evidence of rationality of the very highest order. Given sixty or seventy different kinds of stuff, each with its own proper qualities and attributes, to make out of them a stable and progressive universe-that is the problem; and it is one evidently of a higher kind than that presented to us by Mr. Spencer.

Thus we have the theistic problem and answer before evolution can be said to have begun. Whether these molecules have had a previous history or not, at all events they have passed now out of any sphere which can be influenced by the struggle for existence. A molecule of hydrogen continues to be a molecule of hydrogen wheresoever it may be, in whatsoever combination it may exist, and whatsoever work it may be doing. If it ever had to struggle for existence, it has long ago got past that stage. It exists, it cannot be changed, it does work, and about it evolution has nothing to say. And yet the problem of its existence and its qualities and its relations is as great as those which evolution is called on to solve.

CHAPTER II

EVOLUTION AND LAW

Nature is what is fixed, stated, settled-Law and hypothesis -The nebular theory-Its plausibilities and its difficulties-The nebular theory and evolution-It involves a rational system-The theistic argument-ContinuityEvolution a real process-" Instability of the homogeneous "-Multiplication of effects-"Is the effect more complex than the cause?"-Criticism of this statement.

TH

HE unity of the primitive nebulosity must have been, as we have seen, a unity of elements in relation to one another. It is not undifferentiated stuff, but definite molecules existing in definite relations. It is not chaotic, but orderly, and existing in relations which can be thought. Thus the unity of the primitive nebulosity is already rational and intelligible. If this is possible at the outset, then the process of evolution will also be rational and intelligible, and the outcome will also be rational. It is not for us to contend against the existence of a primitive nebulosity either of the solar system or of the sidereal. Nor have we any interest in contending against the discovery of method, order, law in nature. We are glad to sit at the feet of those who can show us the widening bounds of order and law, who can teach us to know the dominion of order and law

where we were once unable to discover it. We gladly follow Mr. Herbert Spencer as he leads us on from stage to stage of existence and of knowledge, and shows us how every stage is under law, and that even the very discovery of law is itself subject to law. We may not agree with him either in the general or in the particular, but we are grateful for the wide outlook he has cast over the universe, and for a possible interpretation of the order of nature. We had learned from Bishop Butler that the meaning of nature is what is fixed, settled, determined, and that what is fixed and settled has had reference to some cause which made it so.

Thus we were prepared in the interests of theology to welcome every conquest of science and every fresh proof of the universal reign of law. The Bishop had taught us to look for the traces of the Divine footsteps, not in what appears to be lawless and capricious and arbitrary, but in that which was fixed, steadfast, determined. Thus, on the principles of Bishop Butler,-which are also the principles of a true theology,- -we are to wait for the instructions of our masters in science. They are the true interpreters of nature, as they are also the discoverers of its laws. They have proved that the law according to which a stone falls to the ground is the law according to which the planets describe their orbits and the stars maintain their places. And if they

tell us that the earliest known form of the solar system is that of a gaseous nebula, and if they can prove this to be the fact—well, then we accept the fact, and act accordingly. If they tell us that the

widest law known to them is that of evolution, that by the way of evolution the universe has come to be what it is-well, if it is so, we see no more reason why we should be disturbed by evolution than we have been by gravitation. Neither gravitation nor evolution is ultimate, and when science has done its work something remains to be said.

Let us therefore without hesitation follow our scientific teachers, with the sure belief that they do us service whenever they can disclose to us order and method and law in nature. They also will no doubt tell us what has been proven and what is only probable. They will observe, we hope, this distinction, and will give us due notice when they leave the firm ground of proof and take to speculation. And we have a right to expect that they will keep hypothesis separate from ascertained law. For the most part, we have no reason to complain. We get sublime speculation, but we also get profound calculation; and as a rule these are kept separate. With reference to the matter before us, the primitive nebulosity and the nebular theory, for the most part competent men deal with it as a speculation, and not as a certainty. Laplace himself did so. He placed the nebular hypothesis on a different footing from his statement about the stability of the solar system. This was a proof that all the changes of the solar system were periodic, that if it is disturbed a little it will oscillate and return to its old state. This demonstration proceeded on the assumption that the planets were rigid bodies, and on that assumption the demonstration is complete. Corrections have to be made because

the planets are not rigid bodies; but these do not concern us here. The point is that Laplace himself threw out his suggestion of the nebular theory simply as a speculation. The theory of the stability of the solar system followed with inevitable certainty from the theory of gravitation. But the nebular theory could not be deduced from the theory of gravitation, and must continue to rank only as a hypothesis. It has its difficulties, and it has its probabilities; but as yet science does not affirm its truth.

Its probabilities are, to use the language of Sir Robert S. Ball: "Many of the features in the solar system harmonise with the supposition that the origin of the system has been that suggested by the nebular theory. We have already had occasion in an earlier chapter to allude to the fact that all the planets perform their revolution around the sun in the same direction. It is also to be observed that the rotation of the planets on their axes, as well as the movements of the satellites around their primaries, are following the same law, with one slight exception in the case of the Uranian system. A coincidence so remarkable naturally suggests the necessity for some physical explanation. Such an explanation is offered by the nebular theory. Suppose that countless ages ago a mighty nebula was slowly rotating and slowly contracting. In the process of contracting portions of the condensed matter would be left behind. These portions would still revolve round the central mass, and each portion would rotate on its axis in the same direction. As the process of contraction proceeded it would follow from dynamical principles that the