Part 1 (2/2)
The chemist might go on continually manufacturing hydrogen and oxygen, carbon dioxide, ammonia. But he was never to hope to make alcohol, sugar, urea, any of the mult.i.tudinous substances called organic. And now all this folly of forbidding is at an end. The organic bodies are manufactured by man. The inorganic and the organic are no more regarded as clearly distinguishable. Even the chemistry books by their very t.i.tles recognise and proclaim this fact. We have no longer works on organic chemistry. We have volumes on the chemistry of carbon compounds.
In geology the different kinds of rocks graduate into each other.
Between the aqueous, or sedimentary, and the igneous, or those due to the action of fire, range the metamorphic, i.e., sedimentary rocks that have been afterwards subjected to heat. The various systems of sedimentary rocks are known now to be purely artificial if convenient divisions. From the Laurentian up to the recent rocks there has never been any real hiatus. Nowhere is there the slightest evidence of pause or of recommencement. Our groups are artificial. Nature is like Oallio and cares for none of these things.
Whilst rocks thus glide one into the other, the fossil remains that they contain do likewise. If the view of the special creationist were accurate we ought to find isolated forms of dead animals and plants, we ought to find sudden appearances in the rocks of forms not allied to these already encountered, we ought not necessarily to find a series of organic remains ascending in complexity of structure. If the view of the evolutionist is accurate, we ought to find no forms of dead animals or plants isolated; we ought never to find a form appearing without preliminary heralds of its coming in the shape of kindred forms; we ought to find a series of organic remains whose later members are in advance of the earlier. These latter expectations are realised.
In like manner the gap supposed to exist between the kingdoms of the non-living and living is closing up. As long as men had only studied the higher forms of living things there was no difficulty in defining and distinguis.h.i.+ng living organisms. To define and to distinguish the lowest forms of those now known is impossible. How completely this is true can only be understood by those who have studied the protoplasmic ma.s.ses that hover on the border line between the organic and the inorganic. But even the unskilled in microscopic work will be able to grasp something of the great truth if they will take the trouble to look up the innumerable definitions of life that have been given by various persons, and note how unsatisfactory, how contradictory and often self-contradictory they are.
If we pa.s.s up into the kingdoms of the living, and study plants and animals, the same unity of phenomena meets us. Our cla.s.sification terms--order, genus, species, and so forth--are as artificial as our names for the geological systems. No one holds to-day that any single species is clearly marked off from all others. Connecting links abound in our vegetable kingdom. The lichens, long regarded as a separate cla.s.s of lowly organised plants are now known to be fungi that are parasitic upon algae. The higher cryptogams or flowerless plants are found to be at one in their structure and functions with the lower phsenogams or flowering plants.
The distinctions between plants and animals are found to have vanished.
Once again it is easy enough to distinguish high plants from high animals. But no man can satisfactorily draw the line between the lower members of the two kingdoms. The old definitions of the animal and the plant given with a suicidal glibness in old books on botany and zoology, when tried in the balance of criticism, are found wanting. Even the food-distinction, supposed to be the best distinction between the two groups, fails. It is no longer true that plants feed on the inorganic, and animals on organic substances. The cases of vegetable parasites and of insectivorous plants give a direct contradiction to this statement.
And it is very interesting to notice how gradual are the transitions in this as in all cases. A group of plants known as saprophytes, that feed on decaying organic things, is the natural transition between the ordinary plants that eat inorganic food-stuffs, and those plants that, like animals, exist on organic substances. So marked is this difficulty of distinguis.h.i.+ng between the lower plants and the lower animals, that it has been suggested that a third kingdom of the living should be constructed midway between the two generally recognised. This is to be called Protista, and is to include all the doubtful forms that are not clearly members either of the Kingdom Animalia or of the Kingdom Vegetabilia.
If the arbitrary nature of all our systems of cla.s.sification is understood, this new division will do little harm. But for the systematist the difficulty is by the establishment of this group only doubled. Heretofore he had only to struggle over a particular living, thing, with the view to determine whether it were plant or animal. Now he will have to struggle over it with the view of telling whether it is Protistic or animal, or Protistic or vegetable. But the true evolutionist will only look on the group of the Protista as containing forms that represent the parent condition of both vegetables and animals.
The animal kingdom, no less than the vegetable, gives these results.
Amphioxus, the little Mediterranean fish, links the Vertebrata, or back-boned animals, for ever on to the Invertebrata. The cla.s.ses of the Vertebrate sub-kingdom have their connecting links or intermediate forms. These cla.s.ses, adopting for popular exposition the old cla.s.sification, are the Pisces, Amphibia, Eeptilia, Aves, Mammalia.
Whilst Amphioxus at the lower end of the cla.s.s of fishes connects these with the soft-bodied animals, or Mollusca, at the upper end of the Pisces, we have the Lepidosiren, or mud-fish. It is impossible to say whether this animal is more of a fish or a reptile. With limbs rather than fins, with three cavities to its heart, and a swim-bladder that acts as a lung, it has yet so many parts of its anatomy that are piscine as to lead Professor Huxley still to place it as a solitary representative of the highest order of Pisces.
The cla.s.s Amphibia is itself a confirmation of the general truth, for its members, such as the frogs, are in their early condition fish, and in their adult state reptiles. Pterodactyl of the Jura.s.sic strata is the winged lizard. Its name tells us that we have a form intermediate between the cla.s.ses Reptilia and Aves. The duck-billed Platypus, or Ornithorhyncus, of Australia, is a furred mammal that suckles its young, and yet has a bird's bill, a bird's feet, a bird's wis.h.i.+ng-bone, a bird's heart, a bird's alimentary ca.n.a.l. If we turn to the individual cla.s.ses, the same thing obtains. To take but the the highest cla.s.s, the Prosimiae, or half-apes, among the Mammalia are an order, that stands centrally to the Insectivora, Eodentia, Cheiroptera, and Primates. There is no gap between man and the rest of the Primates. Not a single mark of anatomy, of physiology, or of psychology, clearly distinguishes man from the highest apes.
If we study the individual animal, the same fact of the unity of phenomena is again borne in upon us. The bodily functions are by no means so distinct in their nature as we were wont to think. To take but an ill.u.s.tration.
The sense-organs of man are all found to be only so many modifications of the integument.
The skin or tactile organ is the integument. The tongue or taste organ is but the integument folded inwards and a little modified. The nasal cavities are also lined with a modification of the same tissue, and even the most complex sense organs that are at the same time the most important--that is the eye and the ear--are, as the study of development or embryology shows us, only the result of a series of remarkable changes affecting certain parts of the epidermis of the animal.
Those physiological functions of the human body that appear to be clearly marked off are really not completely demarcated. Take as example the excretory action of the skin, lungs, and the renal organs. The lungs get rid especially of carbon dioxide; the skin of water; the renal organs of the products of nitrogenous decay. But each of these organs also eliminates those products which are eliminated by the other two.
Thus the lungs, whilst they get rid princ.i.p.ally of carbon dioxide, also get rid of water in the form of steam and of nitrogenous matter.
The skin gives off a certain quant.i.ty of carbon dioxide and nitrogen excreta. And the renal organs also eliminate all three of the chief forms of excretory matter. When any one of these three organs is not functioning at its best, extra work is thrown upon the others, and in some extreme cases this metastasis, or transference of function, is very remarkable. Thus an ulcer in the human body has been known to secrete milk.
Try to realise at least something of what all this means. It is no longer possible to mark off clearly the various domains of science.
Science is one, for it is the study of nature, and nature is one.
In every branch of our knowledge that daily grows more unified, the transitions are found to be innumerable and the gradations infinitesimal. Our chemical groups, our geological rocks and strata, our inorganic and organic kingdoms, our plants and animals, our cla.s.ses, orders, genera, species, all are seen to be artificial.
Here is then the new message that science is uttering to man. It is in truth good news. There is no break anywhere. The universe is one vast whole. It is true that at first there seems to be a loss because of the indistinctness that now veils the old lines of demarcation. At first some taring of a shock is felt when we realise that the old definitions and cla.s.sifications are only matters of convenience, and really represent nothing in nature. But our view of the whole gains incomparably. We are led to take a larger and more true conception of the universe. If the subdivisions disappear the unity of the whole comes out with wonderful clearness. We study phenomena from below upwards, and see something more than an unbroken series. We see that actually there is no below and no above.' The mineral kingdom of the non-living pa.s.ses into the living. This by gradual stages of ascent rises to the loftiest forms of plants and animals yet known. But these in their constant decay and in their death once for all as individuals, return to the mineral kingdom again. If only we grasp the full meaning of this new gospel founded on science, all life acquires a new significance. Most of all our own life, as the highest expression known to us of the phenomena of matter in motion, becomes more solemn and more full of hope. In it more than in any other are gathered together the forces of the universe. The attraction of the stone for the planet, and of the particles of rock one for another, the loves and hates of chemical atoms, the energies of electrified and magnetised bodies, the variations of innumerable simpler forms of organisms, long chains of heredity reaching back through incalculable times, myriads of adaptations, struggles and failures, deaths and lives, all have met in us. We, more than all others, are the heirs of the ages. While our less fortunate brethren, the lower animals, the plants, the minerals, are playing their good part in the universal history, without the consciousness in full of the meaning of it all, we read the signs of the past and of to-day. ”We know what we are, but we know not what we may be,” in all the detail that our children's children will see and live. Yet we know that the race has a future that will transcend its past, as that past transcended the dark dumb lives of the ancestry whence our kind has sprung.
The Gospel of Evolution is replacing that of Christianity. Science is taking the place of Religion and yielding to mankind the poetry that its forerunner missed. Nature is our all in all. Only the whisper of a secret thought here and there of hers has yet reached our ears. But one. The only good result that is supposed to flow from prayer does not really flow from prayer at all, but is explicable by purely natural facts. It is healthier that people should know these facts, than that they should refer real sensations to an imaginary cause. This special re-action which under certain circ.u.mstances follows, but is not paused by prayer to a supernatural existence, forms but a minute part of the results which flow from belief in prayer. I desire to destroy prayer not only because it is a fraud, but because it is a hindrance to progress.
Men pray to do that which they should link hands to perform for themselves. They are down on their knees, crying like children, when they should be on their feet, working, striving for their fellows. I grudge every moment of time that is given by man to G.o.d. Man wants all we can do; our heart, our brain, our love, our faculties, all, all these are sacred to man; they must not be desecrated to the use of G.o.d. It is sacrilege to steal for G.o.d the wealth needed for the enriching of man.
Why, only a few weeks since I read a letter from the Dean of Peterborough, asking for 40,000 for the repair of Peterborough Cathedral. And men, women and little children are rotting in cellars in the very city wherein that letter was published. And he will get it.
40,000 are given so easily for a house of G.o.d, but 40,000 pence would be grudged to make decent the hovels in which human beings live. I hate the charity which pours out wealth for a G.o.d, and counts in miserly fas.h.i.+on every farthing given for man.
There are no means of progress upon earth save those of study and of work. Study of nature to find out what is; work to apply the knowledge for the increase of human happiness. For centuries upon centuries men have prayed to G.o.d for deliverance from poverty, from misery, from crime; and poverty, misery and crime are found on every side. It is time that we should turn from G.o.d to man, from prayer to work, from dreaming to acting. Man shall do for earth what prayer has failed to do; and man's thought, man's love, man's st.u.r.dy effort shall make that Golden Age for which so many have prayed, but so few have worked.
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