And as to the expectation which he avowed, there appears to be no slight force in the response of his adversary Dr. Bastian:[80]

What reason [he asks] does Professor Huxley give in explanation of his supposition?... The only reason distinctly implied is because the physical and chemical conditions of the earth's surface were different in the past from what they are now. And yet, concerning the exact nature of their differences, or the degree in which the different sets of conditions would respectively favour the occurrence or arrest of an evolution of living matter, Professor Huxley cannot possess even the vaguest knowledge. He chooses to a.s.sume that the unknown conditions existing in the past were more favourable to _Archebiosis_ (life-evolution) than those now in operation. This, however, is an a.s.sumption which may be entirely opposed to the facts.

It is thus hard to understand how Professor Huxley could profess to justify his expectations by verification, for that the above account of the matter is no-wise overstated we have his own acknowledgment:[81]

Of the causes which have led to the origination of living matter, it may be said that we know absolutely nothing.... Science has no means to form an opinion on the commencement of life; we can only make conjectures without any scientific value.

Such a witness as Huxley might well suffice, but the question is so important as to make it advisable to call some others, though only a few amongst many who testify to the same effect.

Like his friend and ally Huxley, Professor Tyndall believed that spontaneous generation had once occurred, and denied that it occurs now.

As to the former article of his creed he was even more p.r.o.nounced in his materialism. We have already heard him proclaim that in matter is to be discerned the promise and potency of all terrestrial life. He likewise inclined to believe that not only life but consciousness is immanent everywhere, in the vegetable and mineral no less than in the animal world,[82] and that not merely life and consciousness, but:

All our philosophy, all our poetry, all our science, and all our art--Plato, Shakespeare, Newton, and Raphael--are potential in the fires of the sun.[83]

Beliefs such as these might be thought to imply that the genesis of life is a simple affair, but Tyndall was no less convinced than Huxley that, as things are, it cannot be obtained without antecedent life on which to draw. Having described the experiments devised to test the matter, he thus concludes:[84]

Here, as in all other cases, the evidence in favour of spontaneous generation crumbles in the grasp of the competent enquirer.

At the same time, he was equally certain that life must have had an inorganic origin and that Science bids us so to believe. His various utterances are not, it is true, very easily reconciled. On the one hand he lays it down that "Without verification a theoretic conception is a mere figment of the intellect." On the other hand in his Belfast Address he thus expressed himself:

Believing, as I do, in the continuity of nature, I cannot stop abruptly where our microscopes cease to be of use. Here the vision of the mind authoritatively supplements the vision of the eye. By a necessity engendered and justified by Science I cross the boundary of the experimental evidence.... If you ask me whether there exists the least evidence to prove that any form of life can be developed out of matter, without demonstrable antecedent life.... [men of science] will frankly admit their inability to point to any satisfactory experimental proof that life can be developed, save from demonstrable antecedent life.

Far, however, from being a mere figment, his mental vision is represented as the most unalloyed product of reason. He writes:[85]

Were not man's origin implicated, we should accept without a murmur the derivation of animal and vegetable life from what we call inorganic nature. The conclusion of pure intellect points this way and no other.

The conclusion of pure intellect, however, having nothing to show for itself in the way of evidence, we are again referred to a condition of things concerning which we know, and can know, nothing.

Supposing [writes the Professor][86] a planet carved from the sun, set spinning round an axis, and revolving round the sun at a distance from him equal to that of our earth, would one of the consequences of its refrigeration be the development of organic forms? I lean to the affirmative.

It is no doubt interesting to know to what opinion the Professor inclined, but is this sort of thing Science?

In the same manner Mr. Herbert Spencer, the philosopher of evolution _par excellence_, thus reports:[87]

Biologists in general agree that in the present state of the world no such thing happens as the rise of a living creature out of non-living matter. They do not deny, however, that at a remote period in the past, when the temperature of the surface of the earth was much higher than at present, and other physical conditions were _unlike those we know_,[88] inorganic matter, through successive complications, gave origin to organic matter.[89]

Mr. Darwin himself, who is constantly supposed to have upheld, or even to have demonstrated, the fact of spontaneous generation, is amongst the strongest witnesses against it. He was indeed disposed to believe that the living will some day be found to be producible from the lifeless, the ground of his expectation being the "Law of Continuity,"[90] or the a.s.sumption that from the beginning of nature to the end one only kind of law uniformly operates, namely the same as we now experience. But this is to a.s.sume the whole question at issue, for unless it can be shewn that there has been spontaneous generation, we cannot be a.s.sured that there is such a Law of Continuity. And despite his expectation Darwin always denied that the origin of life has been--sometimes even that it can be--explained. Thus he wrote on various occasions:

It is mere rubbish thinking at present of the origin of life; one might as well think of the origin of matter.[91]

As for myself I cannot believe in spontaneous generation, and though I expect that at some future time the principle of life will be rendered intelligible, at present it seems to me beyond the confines of Science.[92]

No evidence worth anything has as yet, in my opinion, been advanced in favour of a living being, being developed from inorganic matter.[93]

Here we may conveniently pause and take stock of our results. On the one hand, we are bidden in the name of Science to learn the past from the present, and the present from observation and experiment alone. On the other, we are invited to believe in an occurrence which observation and experiment negative in the present, on the ground that the circ.u.mstances must once have been entirely different from any with which we are acquainted. Obviously, the real motive of belief is that navely expressed by Professor Haeckel, who tells us that spontaneous generation is proved by the doctrine of Evolution;[94] which then in its turn is proved by spontaneous generation.

Two points must however be noticed in which it is attempted to find present evidence in favour of spontaneous generation.

First, there is Protoplasm--the "Physical Basis of Life," or Living Matter, being that form of matter by which life is always accompanied.

In this no chemical element unknown elsewhere, is to be found; the cells of which it consists are compounded of Oxygen, Hydrogen, Nitrogen, and Carbon; and it has been argued, especially by Huxley, that it is therefore not different in kind from other compounds; that as Oxygen and Hydrogen form water, Oxygen and Carbon, Carbonic Acid, Hydrogen and Nitrogen, Ammonia,--so the four combined, in proper circ.u.mstances and proportions, make Living Matter, without the aid of any vital force or principle. And Haeckel with his habitual audacity foretells the artificial production of Protoplasm for purposes of commerce. But, as Mr. Stirling observes,[95] man has always known that he is made of dust, and that the only part of him perceptible to sense is substantially the same as the earth beneath his feet. All that he now learns in addition is that when such matter is wedded to life it undergoes marvellous transformations which in part at least we are able to recognize, but are wholly unable to comprehend. This Professor Huxley himself admits:

The properties of living matter [he writes][96] distinguish it absolutely from all other kinds of things, and the present state of knowledge furnishes us with no link between the living and the not-living.

Not only that: the subject is full of complexities of which Professor Huxley gives no hint, and which it would even seem he did not himself perceive. In his celebrated lecture on the Physical Basis of Life[97] he gives his hearers to understand that all Protoplasm is the same, that its particles are as the bricks with which any sort of edifice may be constructed, a cathedral or a gin-shop, a palace or a hovel. The protoplasm of a mushroom, for instance, he declares to be essentially identical with that of him who eats it, into which it is most readily convertible. He also speaks of the effect of eating mutton being to "transubstantiate sheep into man." But, positive as are these statements, they are far from representing scientific truths, and we are told by Sir William Thiselton-Dyer that he himself would not know what to do with a candidate who should advance such views in an examination.[98] As to the mushroom and the mutton, Sir William adds, that except the definition of a crab, as a red fish that runs backwards, attributed to the French Academy, he can call to mind no statement "so compact of error."

In reality, instead of all Protoplasm being the same, the differences are infinite. Particles from different sources may be indistinguishable by the microscope or by any test that chemistry can apply, but this only increases the mystery of their nature, for each has its own functions and will perform no others. The Protoplasm of a plant will do what that of an animal, seemingly identical, cannot do. That of a fish will convert the same nutriment into quite a different formation from that of a man.

It is no doubt true that a particle of fungoid differs in no appreciable physical respect from one of human protoplasm, yet the former will never emerge from the fate of the humble mushroom, while the other may be instinct with the thoughts of a Prime Minister.[99]

As Mr. Stirling sums up the matter:[100]

There is nerve-protoplasm, brain-protoplasm, bone-protoplasm, muscle-protoplasm, and protoplasm of all the other tissues, no one of which but produces only its own kind, and is uninterchangeable with the rest. Lastly, we have the overwhelming fact that there is the infinitely different protoplasm of the various infinitely different plants and animals, in each of which its own protoplasm, as in the case of the various tissues, but produces its own kind, and is uninterchangeable with that of the rest.

It thus appears that the character of Protoplasm, far from making it easier to conceive the mechanical production of living things, does but immensely aggravate the difficulty. As Sir William Thiselton-Dyer avows: "I do not see even the beginning of a materialistic theory of protoplasm." And Haeckel's idea that we shall succeed in creating organic life does not commend itself to such an authority as Sir Henry Roscoe:

It is true [he says][101] that there are those who profess to foresee that the day will arise when the chemist, by a succession of constructive efforts may pa.s.s beyond alb.u.men, and gather the elements of lifeless matter into a living structure. Whatever may be said of this from other standpoints, the chemist can only say that at present no such problem lies within his province.

Protoplasm, with which the simplest manifestations of life are a.s.sociated, is not a compound, but a structure built up of compounds. The chemist may successfully synthesize any of its component compounds, but he has no more reason to look forward to the synthetic production of the structure than to imagine that the synthesis of gallic acid leads to the artificial production of gall-nuts.

And M. de Quatref.a.ges thus sums up the conclusions at which he arrives from minute study of the lowest forms of life:[102]

I make bold to affirm that the deeper Science penetrates into the secrets of organization and phenomena, the more does she demonstrate how wide and how profound is the abyss which separates brute matter from living things.

The other point requiring notice is crystallization. Inorganic matter, as we know, can build up crystals, the wonderful structure of which results from the molecular properties of the substance crystallized. Why then, some would ask, may not matter in the same manner produce Protoplasm?

But, in the first place, this, as we have heard, is what it is never found to do. Crystals we can produce at pleasure, in what quant.i.ty we will. But all efforts have not yet succeeded in obtaining the most minute speck of living matter. Moreover, nothing can be more widely different from organic structures than crystals. The latter are always mathematical, the former never: the latter grow by outside accretion, of the one kind of particles whereof they consist: the former by absorption and a.s.similation of various foreign substances: the latter are wholly independent of anything like an ancestor: for the former an ancestor is in our experience indispensable: crystals can be dissolved and recrystallized: living matter once destroyed can never be reconst.i.tuted.

Above all, the particles incorporated in the crystal are absolutely quiescent, so far as any portion of matter can be said to be so, no more able to change their position without external force than the bricks in a wall, while those in living tissue at once become subject to "the whirlwind of life," involving constant change the cessation of which is death.

It is inexplicable to me [says M. de Quatref.a.ges][103] that some men whose merits I otherwise acknowledge, should have compared crystals to the simplest living forms.... These forms are the antipodes of the crystal from every point of view.

To the same effect speaks Mr. A. R. Wallace, Mr. Darwin's a.s.sociate in the discovery of the Darwinian theory. In a work expressly devoted to the vindication of that theory, Mr. Wallace declares that far from the way of evolution being made clear by Science from end to end--"there are at least three stages in the development of the organic world where some new cause or power must necessarily have come into action." And at the head of them he places that which we are now considering, writing thus:[104]

The first stage is the change from inorganic to organic, when the earliest vegetable cell, or the living protoplasm out of which it arose, first appeared.... There is in this something quite beyond and apart from chemical changes however complex; and it has been well said that the first vegetable cell was a new thing in the world, possessing altogether new powers....[105]

Such testimonies are sufficient for our present purpose. In face of them it cannot be pretended that Science _knows_ anything of spontaneous generation or gives her verdict in its favour. On the contrary, as Professor Tait declares:[106]

To say that even the very lowest form of life, not to speak of its higher forms, still less of volition and consciousness, can be fully _explained_ on physical principles alone, ... is simply unscientific. There is absolutely nothing known in physical science which can lend the slightest support to such an idea.... To suppose that life, even in its lowest form, is wholly material, involves either a denial of the truth of Newton's laws of motion, or an erroneous use of the term "Matter." Both are alike unscientific.

Yet it is precisely in the name of Science that we have been told to accept the spontaneous origin of life from inorganic matter, as a clearly demonstrated truth, and no riddle at all.

But as Professor Virchow, Evolutionist and Materialist as he was, well said in regard of this very point in the Munich Congress of 1877:

If we would speak frankly, we must admit that naturalists may well have some little sympathy for the _generatio aequivoca_ [spontaneous generation]. If it were capable of proof, it would indeed be beautiful! But, we must acknowledge, it has not yet been proved. The proofs of it are still wanting.... Whoever recalls to mind the lamentable failure of all the attempts to discover a decided support for the _generatio aequivoca_ in the lower forms of transition from the inorganic to the organic world, will feel it doubly serious to demand that this theory, so utterly discredited, should be in any way accepted as the basis of all our views of life.