I trust that by the use of the term "economy" in speaking of what is observable in the works of the Creator, I shall be understood as comprehending both the avoidance of unnecessary and the exertion of all necessary power. Of the degree of necessity in any exercise of a power which we suppose to be infinite, we can only judge by what we can see. If omnipotence and omniscience are to be predicated of the being who is supposed to preside over the universe, it is rational to conclude, from all that we can discover, that, in applying a uniform system of construction to different animals of a certain general class, he acted upon a principle that his unerring faculties enabled him to see was a comprehensive one; and that in producing variations of that system of construction that would result in adapting its uniformity to the varying conditions of the different species, he acted by the same boundless wisdom and power. If these postulates of the Divine attributes are conceded, rudiments do not by any means necessarily lead to the conclusion that all the animals of a certain class are co-descendants from some remote common progenitor, for they do not exclude the hypothesis that each distinct animal was formed upon a general plan of construction that could be applied throughout the class, but that it was varied according to the special conditions of its intended being. Organs or parts may thus have become more or less rudimentary without resorting to the supposition of a common progenitor for the whole class. That supposition, indeed, makes it necessary to assume that the infinite Creator fashioned some one animal, and then, abstaining from all work of further direct creation, left all the other animals to be evolved out of that one by the operation of secondary causes that fail even as a theory to account for what we see, and that can not be traced through any results that have yet been discovered. Wherever we pause in the ascending scale of the Darwinian descent of man, wherever we place the first special act of creative power, whether we put it at the fish-like animal of the most remote antiquity, and call that creature the original progenitor of all the vertebrata, or whether we suppose a special creation to have occurred at the introduction of the mammalian series, or anywhere else, we have to account for changes of system, new constructions, elaborately diversified forms, by the operation of agencies that were incapable of producing the results, if we are to judge of their capacity by anything that we have seen or known of their effects.

I will conclude this chapter by expressing as accurately as I can what has struck me as the excessive tendency of modern science to resolve everything into the operation of general laws, or into what we call secondary causes. I may be able to suggest nothing new upon this part of the subject, but I shall at least be able, I hope, to put my own mind in contact with that of the reader by explaining what has impressed me in the speculations of those who lay so much stress upon the potency of general laws to produce the results which we see in Nature. Of course, I do not question the great fact that the infinite Power acts by and through the uniform methods from which we are accustomed to infer what we call laws; which in physics is nothing but a deduction of regularity and system from that which we see to be perpetually and invariably happening. Now, I do not enter here into the question of the tendency of modern science to displace our religious ideas of a special Providence, by attributing everything in Nature to the operation of fixed laws of matter; or its tendency, in other words, to remove the infinite Being at a greater distance from us than that in which our religious feelings like to contemplate him. I am perfectly sensible that in truth the infinite God is just as near to us, when we regard him as acting by general laws and secondary causes, as when we believe him to be exercising a direct and special power. I am equally sensible that it is in the very nature of infinite power, wisdom, and benevolence to be able and willing to ordain uniform and fixed principles of action. That Power which gives to matter all its properties may well be supposed to have established uniformity and regularity of movements, forces, combinations, and qualities. How supremely consistent this uniformity and regularity are, with what stupendous accuracy they are kept forever in operation, we are more or less able to discern; and that benevolence which is believed to accompany the power may well be supposed to have intended that its intelligent and rational creatures should be able in some degree to discover and to avail themselves of these unvarying laws of the physical world. But are these laws to be supposed to be the only methods by which the infinite Will has ever acted? Is it to be assumed that, having settled and established these perpetual principles, on which matter, organized or unorganized, is to act, he leaves everything to their operation and abstains from all further exertion of his creative power for any special purpose? Has he given to these general laws a potency to produce, in and of themselves, all the results? In other words, has he affixed to their operation no limitations, or has he set bounds to them, and reserved to himself, by direct, specific, and occasional exercise of his will and power, for new purposes, to produce results for which the general laws were not ordained?

It is not necessary here to enter into the consideration of what are called "miracles." These, in their true meaning, are special interpositions, which the Divine Power is supposed to make, by a suspension or interruption of the established laws of Nature; and, whatever may be the grounds of our belief or our unbelief in such occurrences, they are not exercises of power such as those which are supposed to take place in special creations of new beings. That the hypothesis of special creations of new beings involves no interruption or displacement of the fixed laws of Nature, is quite manifest.

Note A.

Note on Amputation, or Severance of Parts.—As Mr. Darwin attached some importance to a fact which he asserted respecting the efforts of Nature to restore a part of an organism which has been severed by amputation, I think it well to quote his statement, and to point out what I believe to be an inaccuracy. His statement is this: "His [man's] wounds are repaired by the same process of healing, and the stumps left after the amputation of his limbs, especially during an early embryonic period, occasionally possess some power of regeneration, as in the lowest animals." It is not quite apparent what he means by amputation during an early embryonic period. If he is to be understood as referring to a case of complete severance of any part of an embryo before birth, it has not been demonstrated that such a severance has been followed by a successful effort of Nature to replace the severed part; and it is difficult to understand how there could be such an amputation during embryonic life without destroying the life of the embryo; or, if the severed part were one of the extremities, how there could be a new extremity formed. In such a case, if life continued and birth were to take place, the animal must be born in an imperfect state. In regard to amputations taking place at any time after birth, if the expression "some power of regeneration" means to imply a new formation to take the place of the severed part, the assertion is not correct. What occurs in such cases may be illustrated by the very common accident of the severance of the end of a human finger at the root of the nail. If the incision is far enough back to remove the whole of the vessels which secrete the horny substance that forms the nail, there will be no after growth of anything resembling a nail. If some of those vessels are left in the stump, there will be continuous secretion and deposit of the horny substance, which may go so far as to form a crude resemblance to a nail. But if all the vessels which constitute the means of perpetuating a perfect nail are not left in their normal number and action, there can be no such thing as the formation of a new nail. Whether it is correct to speak of the imperfect continuation of a few of the vessels to secrete the substance which it is their normal function to secrete, as a "power of regeneration," is more than doubtful, if by such a power is meant a power to make a new and complete structure to take the place of the structure that has been cut away. It is nothing more than the continued action of a few vessels, less in number than the normal system required for the continued growth and renewal of the part in question. The abortive product in such cases looks like an unsuccessful effort of Nature to make a new structure in place of the old one; but it is not in reality such an effort. The fact that the same thing occurs, in just the same way and to a corresponding extent, in different animals, has no tendency to prove anything excepting that these different animals share the same general system of secreting vessels for the formation and perpetuation of the several parts of their structures. It has no tendency to prove that they are co-descendants from a common ancestral stock, for on the hypothesis of their special and independent creation a common system of secreting vessels would be entirely consistent with their peculiar and special constructions.