One way of replying to this question is indicated in the following passage, which we have quoted at length from an article upon "The Atomic Theory of Lucretius," in the North British Review for March 1868:

"It is a principle of mechanics that a force acting at right angles to the direction in which a body is moving does no work, although it may continually and continuously alter the direction in which the body moves. No power, no energy, is required to deflect a bullet from its path, provided the deflecting force acts always at right angles to that path.

<< 'If you believe in free-will and in atoms, you have two courses open to you. The first alternative may be put as follows: Something which is not atoms must be allowed an existence, and must be supposed capable of acting on the atoms. The atoms may, as Democritus believed, build up a huge mechanical structure, each wheel of which drives its neighbour in one long inevitable sequence of causation; but you may assume that beyond this ever-grinding wheelwork there exists a power not subject to but partly master of the machine; you may believe that man possesses such a power, and if so, no better conception of the manner of its action could be devised than the idea of its deflecting the atoms in their onward path to the right or left of that line in which they would naturally move. The will, if it so acted, would add nothing sensible to nor take anything sensible from the energy of the universe. The modern believer in free-will will probably adopt this view, which is certainly consistent with observation, although not proved by it. Such a power of moulding circumstances, of turning the torrent to the right, where it shall fertilise, or to the left, where it shall overwhelm, but in nowise of arresting the torrent, adding nothing to it, taking nothing from it,—such is precisely the apparent action of man's will; and though we must allow that possibly the deflecting action does but result from some smaller subtler stream of circumstance, yet if we may trust to our direct perception of free-will, the above theory, involving a power in man beyond that of atoms, would probably be our choice. . . . "We cannot hope that natural science will ever lend the least assistance towards answering the Free-will and Necessity question. The doctrines of the indestructibility of matter and of the conserva

tion of energy seem at first sight to help the Necessitarians, for they might argue that if free-will acts it must add something to or take something from the physical universe, and if experiment shows that nothing of the kind occurs, away goes free-will; but this argument is worthless, for if mind or will simply deflects matter as it moves, it may produce all the consequences claimed by the Wilful school, and yet it will neither add energy nor matter to the universe."

230. Now there appears to us to be a very serious objection to this method of regarding the position of life, unless it be somewhat modified. Let us take one of the visible masses of this present universe, such as a planet. Instead of being 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 disappears 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 and energy; 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