The problem to be solved—and an old-world problem indeed it is—is the range, and especially the nature, of the connection between mind and matter; or, let us say, between the material universe on the one hand, and the vital, the mental, the conscious and spiritual universe or universes, on the other.
It would be extremely surprising if any attempt yet made had already been thoroughly successful, though the attack on the idealistic side appears to many of us physicists to be by far the most hopeful line of advance. An excessively wide knowledge of existence would seem to be demanded for the success of any such most ambitious attempt; but, though none of us may hope to achieve it, many may strive to make some contribution towards the great end; and those who think they have such a contribution to make, or such a revelation entrusted to them, are bound to express it to the best of their ability, and leave it to their contemporaries and successors to assimilate such portions of it as are true, and to develop it further. From this point of view Professor Haeckel is no doubt amply justified in his writings; but, unfortunately, it appears to me that although he has been borne forward on the advancing wave of monistic philosophy, he has, in its specification, attempted such precision of materialistic detail, and subjected it to so narrow and limited a view of the totality of experience, that the progress of thought has left him, as well as his great English exemplar, Herbert Spencer, somewhat high and dry, belated and stranded by the tide of opinion which has now begun to flow in another direction. He is, as it were, a surviving voice from the middle of the nineteenth century; he represents, in clear and eloquent fashion, opinions which then were prevalent among many leaders of thought—opinions which they themselves in many cases, and their successors still more, lived to outgrow; so that by this time Professor Haeckel's voice is as the voice of one crying in the wilderness, not as the pioneer or vanguard of an advancing army, but as the despairing shout of a standard-bearer, still bold and unflinching, but abandoned by the retreating ranks of his comrades as they march to new orders in a fresh and more idealistic direction.
CHAPTER IV
MEMORANDA FOR WOULD-BE MATERIALISTS
The objection which it has been found necessary to express concerning Materialism as a complete system is based not on its assertions, but on its negations. In so far as it makes positive assertions, embodying the results of scientific discovery and even of scientific speculation based thereupon, there is no fault to find with it; but when, on the strength of that, it sets up to be a philosophy of the universe—all inclusive, therefore, and shutting out a number of truths otherwise perceived, or which appeal to other faculties, or which are equally true and are not really contradictory of legitimately materialistic statements—then it is that its insufficiency and narrowness have to be displayed.
It will be probably instructive, and it may be sufficient, if I show that two great leaders in scientific thought (one the greatest of all men of science who have yet lived), though well aware of much that could be said positively on the materialistic side, and very willing to admit or even to extend the province of science or exact knowledge to the uttermost, yet were very far from being philosophic Materialists or from imagining that other modes of regarding the universe were thereby excluded.
Great leaders of thought, in fact, are not accustomed to take a narrow view of existence, or to suppose that one mode of regarding it, or one set of formulæ expressing it, can possibly be sufficient and complete. Even a sheet of paper has two sides: a terrestrial globe presents different aspects from different points of view; a crystal has a variety of facets; and the totality of existence is not likely to be more simple than any of these—is not likely to be readily expressible in any form of words, or to be thoroughly conceivable by any human mind.
It may be well to remember that Sir Isaac Newton was a Theist of the most pronounced and thorough conviction, although he had a great deal to do with the reduction of the major Cosmos to mechanics, i.e. with its explanation by the elaborated machinery of simple forces; and he conceived it possible that, in the progress of science, this process of reduction to mechanics would continue till it embraced nearly all phenomena. (See extract below.) That, indeed, has been the effort of science ever since, and therein lies the legitimate basis for materialistic statements, though not for a materialistic philosophy.
The following sound remarks concerning Newton are taken from Huxley's Hume, p. 246:—
"Newton demonstrated all the host of heaven to be but the elements of a vast mechanism, regulated by the same laws as those which express the falling of a stone to the ground. There is a passage in the preface to the first edition of the Principia, which shows that Newton was penetrated, as completely as Descartes, with the belief that all the phenomena of nature are expressible in terms of matter and motion:—
"'Would that the rest of the phenomena of nature could be deduced by a like kind of reasoning from mechanical principles. For many circumstances lead me to suspect that all these phenomena may depend upon certain forces, in virtue of which the particles of bodies, by causes not yet known, are either mutually impelled against one another, and cohere into regular figures, or repel and recede from one another; which forces being unknown, philosophers have as yet explored nature in vain. But I hope that, either by this method of philosophising, or by some other and better, the principles here laid down may throw some light upon the matter.'"