attracted to a fixed and visible centre of force such as the sun, suppose for a moment that it is bound to an invisible and vagrant centre, of which the only condition imposed upon its irregularities is that it shall always move in such a manner that there shall be no creation nor destruction of energy.

We have only to imagine for a moment such a universe in order to realise the inextricable confusion into which its intelligent inhabitants would be plunged by the operation of a viewless and unaccountable agency of this nature. No doubt the hypothesis regarding life, which we have quoted above, limits this mode of action to the molecular motions of matter, but if our line of argument has been followed throughout, the reader will probably acknowledge that the superior intelligences of the universe may have the same appreciation of molecular motions that we have of those of large masses. Now they would in turn be put to inextricable confusion by the advent of an unperceivable, and, from the nature of the case, irresponsible force entitled will operating towards the deflection of these molecular motions, even although the energy of the universe should remain the same. We think that Professor Huxley and those who have opposed this mode of regarding the position of life have been somewhat unjustly blamed. They have driven the operation of that mystery called life or will out of the objective universe, or that portion of things which is capable of being scientifically studied by intelligence, and in so doing they have most assuredly done right. The mistake made (whether by this party or their adversaries) lies in imagining that by this process they completely get rid of a thing so driven before them, and that it disappears from the universe altogether. It does no such thing. It only dis

appears from that small circle of light which we may call the universe of scientific perception.

But the greater the circle of light (to adopt the words of Dr. Chalmers), the greater the circumference of darkness, and the mystery which has been driven before us looms in the darkness that surrounds this circle, growing more mysterious and more tremendous as the circumference is increased. In fine, we have already remarked that the position of the scientific man is to clear a space before him from which all mystery shall be driven away, and in which there shall be nothing but matter and certain definite laws which he can comprehend. There are however three great mysteries (a trinity of mysteries) which elude, and will for ever elude his grasp, and these will persistently hover around the border of this cleared and illuminated circle,— they are the mystery of matter; the mystery of life; and the mystery of God,--and these three are one.

231. But in this latter statement we have transgressed the limits of our inquiry, and are content to be driven back. Suffice it to say that these three gigantic mysteries will persistently hover around the illuminated circle, or to speak more properly, the illuminated sphere of scientific thought, of which duration, extension, and structural complexity may be regarded as the three rectangular axes in each of which the process of development goes on simultaneously as the boundary of the sphere is enlarged.

Within this sphere we have only that which can be grasped by Physical Science, but we are not therefore to infer that matter and the laws of matter have a reality and a permanence denied to intelligence.

It is rather because they are at the bottom of the list— are in fact the simplest and lowest of the three-that they

are capable of being most readily grasped by the finite intelligences of the universe. The following words of Professor Stokes, in his presidential address to the British Association at Exeter, occur to us as very clearly embodying this thought :

...

Admitting to the full as highly probable, though not completely demonstrated, the applicability to living beings of the laws which have been ascertained with reference to dead matter, I feel constrained at the same time to admit the existence of a mysterious something lying beyond, a something sui generis, which I regard, not as balancing and suspending the ordinary physical laws, but as working with them and through them to the attainment of a designed end. What this something which we call life may be is a profound mystery. . . . When from the phenomena of life we pass on to those of mind, we enter a region still more profoundly mysterious. We can readily imagine that we may here be dealing with phenomena altogether transcending those of mere life, in some such way as those of life transcend, as I have endeavoured to infer, those of chemistry and molecular attractions, or as the laws of chemical affinity in their turn transcend those of mere mechanics. Science can be expected to do but little to aid us here, since the instrument of research is itself the object of investigation. It can but enlighten us as to the depths of our ignorance, and lead us to look to a higher aid for that which most nearly concerns our well-being."

232. In fine, the Physical properties of matter form the alphabet which is put into our hands by God, the study of which will, if properly conducted, enable us more perfectly to read that Great Book which we call the Universe.

We have begun to recognise some of the chief letters of this alphabet, and even to put two and two together; and, like an intelligent but somewhat conceited child, we are very proud of our achievement. Like such a child we have not yet, however, completely grasped the fact that these letters are only symbols, but look upon them with intense awe as

the great thing in the world, meaning of course our world. We look with a sort of adoration towards those pages in which there are words of two syllables, and are ready to fall down at the feet of that older and wiser child who has penetrated into the depths of such profound mysteries. Our belief is that all knowledge is made for the alphabet just as the little musician believes that all music is made for the piano.

233. Life, then, whatever be its nature, may be supposed to penetrate into the structural depths of the universe. Its seat is in a region inaccessible to human inquiry and equally inaccessible, we may well suppose, to the inquiries of the higher created intelligences. Intimations of its presence are no doubt constantly emerging from this region of thick darkness into the objective universe, but when they have reached it they obey the ordinary laws of phenomena, according to which a material effect implies a material antecedent.

Notwithstanding all this, life exists just as surely as the Deity exists. For we have subjected both these mysteries to the same process, and have found it as difficult to rid ourselves of the one as of the other.

We have driven the creative operation of the Great First Cause into the durational depths of the universe,-into the eternity of the past,—but for all that we have not got rid of God. In like manner we have driven the mystery of life into the structural depths of the universe,—that region of thick darkness which no created eye is able to pierce, but we have not got rid of life, nor are we likely to do so. Before concluding this digression upon the place of life, let us briefly review the attempts made to account for the origin of life by those who have yet fallen short of the scientific conception of an Unseen Universe.

234. Sir W. Thomson has gone further than any one else in such inquiries. We have already alluded to his attempt to explain the origin of the material universe by the vortex ring hypothesis, and also to his other attempt to explain gravitation by the modification of the hypothesis of ultramundane corpuscles. If we add to these his attempt to explain the origin of life as consistently as possible with the principle of Continuity, we think it must be acknowledged that he is a true pioneer in such inquiries as those of this volume as well as in the more ordinary branches of Physical Science.

The explanation of the origin of life proposed by Sir W. Thomson had also occurred independently to Professor Helmholtz. This latter physicist, in an article on the use and abuse of the deductive method in Physical Science,1 tells us very clearly what led himself, and no doubt Sir W. Thomson likewise, to suggest the meteoric hypothesis as a possible way of accounting for the origin of life :—“ If failure attends all our efforts to obtain a generation of organisms from lifeless matter, it seems to me (says Professor Helmholtz) a thoroughly correct procedure to inquire whether there has ever been an origination of life, or whether it is not as old as matter, and whether its germs, borne from one world to another, have not been developed wherever they have found a favourable soil."

235. We have already sufficiently pointed out that the man of science objects to separate creations, and that, in consequence, he tries to explain the present terrestrial life by means of a single primordial germ. But the difficulty still remains regarding the original appearance of this germ. Now, according to the meteoric hypothesis this germ may

1 Nature, January 14, 1875.