Читать книгу The Old Riddle and the Newest Answer - Gerard John - Страница 8
V
WHAT IS A "LAW OF NATURE"?
ОглавлениеAS we have seen, the doctrine of Evolution is presented by its advocates as being based upon the existence of a "Law of Evolution," or "Law of Substance," which both brings about evolutionary processes, and certifies us of their occurrence, so that we may appeal to it as an authority for our belief in the facts of evolution themselves. Thus as Professor Milnes Marshall told the British Association,22
The doctrine of descent, or of evolution, teaches us that as individual animals arise, not spontaneously, but by direct descent from pre-existing animals, so also is it with species, with families, and with larger groups of animals, and so also has it been for all time.
It is not said, be it observed, that the establishment of such facts teaches us the doctrine of evolution, but that the doctrine assures us of the facts; and the utterances constantly met with, of which the above is a fair sample, have no signification if they do not mean this. In the same way Professor Haeckel declares23 that his fundamental cosmic law "establishes" the eternal persistence of matter and force, and their unvarying constancy throughout the entire universe, becoming thus "the pole-star that guides our Philosophy through the mighty labyrinth to a solution of the world problem," and the key to this supreme problem, he further tells us,24 is found in one magic word – Evolution.
It would certainly appear from all this, that by "Evolution" we are to understand some sort of entity at the back of the world, with power at its disposal capable of effecting all its operations, – something in fact remarkably like the First Cause of which we are in search, – and that by its "Laws" are signified some definite forces, the practical action of which has been ascertained by us, so that we can foretell the course of events under them, as we can that of the planets or the tides under the influence of gravitation.
But is it scientific, or even intelligible, to use words thus, and to assign any such significance to such terms as "Law of Evolution," "Law of Substance," or any other "Law of Nature"? We are repeatedly warned to the contrary by so high an authority as Professor Huxley. Once, for instance, he discovered in a sermon of Canon Liddon's this "fallacious employment of the name of a scientific conception," for which it was however added, the preacher "could find only too many scientific precedents."25 This fallacious use of terms, which nowise differs from that under consideration, Professor Huxley thus denounces:
It is the use of the word "law" as if it denoted a thing – as if a "law of nature," as science understands it, were a being endowed with certain powers, in virtue of which the phenomena expressed by that law are brought about… All I wish to remark is that such a conception of the nature of "laws" has nothing to do with modern science… A law of nature, in the scientific sense, is the product of a mental operation upon the facts of nature which come under our observation, and has no more existence outside the mind than colour has. The law of gravitation is a statement of the manner in which experience shows that bodies, which are free to move, do, in fact, move towards one another… The tenacity of the wonderful fallacy that the laws of nature are agents, instead of being, as they really are, a mere record of experience, upon which we base our interpretations of that which does happen, and our anticipation of that which will happen, is an interesting psychological fact: and would be unintelligible if the tendency of the human mind towards realism were less strong.
A law, accordingly, "is not a cause but a fact,"26 and we must learn laws from facts, not facts from laws. It is indeed evident on a moment's thought, that to speak of the Law of Evolution as causing things to be evolved, is like saying that the law of growth makes things grow. Till we know what happens, there is nothing of which Science can take account.
True scientific teaching, I cannot too often repeat [says Professor Tait]27 requires that the facts, and their necessary consequences alone, should be stated, as simply as possible.
In like manner Professor Huxley,28 undertaking to vindicate full scientific value for his own favourite Biology, does so by pointing out that biological methods are similar to those of every other branch of Science, since they begin with the observation of facts, and from this proceed to various applications of the knowledge so acquired. And Professor Haeckel himself tells us regarding his own mode of procedure:29
The means and methods we have chosen for attaining the solution of the great enigma do not differ, on the whole, from those of all purely scientific investigation: firstly, experience; secondly, inference.
Therefore, although the phrases we have already heard from him, are found when scrutinized to be only phrases, which explain nothing, it may be supposed that he elsewhere produces such proofs of his doctrine as will place it on a scientific basis. For these we will now seek.
22
Presidential Address, Section D, Zoology, Leeds, 1890.
23
Riddle of the Universe, p. 2.
24
Ibid., p. 83.
25
"Pseudo-Scientific Realism," Collected Essays, i, 68, 74-78.
26
Newman, Grammar of Assent, p. 72. A "Law of Nature," as has already been said, is simply a statement of what de facto has always been found to occur under certain conditions, and may consequently be expected again. It is obvious however that such expectation is implicitly based on the existence of some cause capable of ensuring the result.
27
"The Teaching of Natural Philosophy," Contemporary Review, Jan., 1878.
28
Lay Sermons, p. 83.
29
Riddle of the Universe, p. 6.