The forms of scientific error change rapidly; only the principle always remains. But this principle requires to be clothed from time to time in new garments, which rejuvenate and disguise it. The system of Lamarck, for a moment popular on account of the philosophic ideas to which it gave support, could not maintain itself in lasting honor in science. It was as it were buried in deep oblivion, when Darwin undertook to awaken it from its ashes by substituting for the antiquated conceptions new ones, destined to give a similar satisfaction to the passions which had applauded the enterprise of Lamarck.
The work of Darwin—we must do him the justice to say it—is an important work, and displays rare science. The author, gifted with great penetration, employs to the greatest advantage what he knows to deduce from it what he does not know; and if he goes beyond experience, it is always in appealing to experience; so that he seems to remain faithful to observation even when he ventures far beyond its limits. Nevertheless so much science and sagacity can hardly blind us to the radical weakness of the system; and it would not have met with so favorable a reception if all the prejudices of the materialists whom it satisfied had not become its ardent champions. A first fact strikes one who studies impartially the theory of Darwin, namely, the incalculable disproportion between the means of demonstration and the immense problem to be resolved. There is question, let it be remembered, of the origin of living species. Darwin tries to explain this origin by the action of a natural selection, incessantly at work, which draws the collection of organisms out of one or several primitive, simple, and rudimentary types formed by the simple action of forces proper to matter. This natural selection is the image of the method according to which new races of domestic animals have been created, as the modern doctors maintain. In order that this, natural selection should produce the powerful effects which Darwin gives to it, he imagines two agents always active—changes in the conditions of existence, and especially vital concurrence. The changes in the conditions of existence, the accidental characters acquired by a living individual and transmitted by inheritance to its descendants, create certain varieties of type. Vital concurrence, the battle of life, the struggle of animated beings to subsist, allow only some of those varieties to last on the scene of the world; the others are vanquished and disappear. These transformations, continued and accumulated from age to age, increased by the indefatigable labor of an immense number of ages, have produced all the animal species actually existing; which are imperceptibly their predecessors in a continuous line of transformation, under the permanent influence of the same natural forces.
The notion of species as well as that of variety and race disappear in this order of ideas, or at least lose the determined sense which the naturalists had attributed to them. Variety and race become species in the way of transformation, in course of development. The living form passes insensibly and by eternal motion from the one to the other, from the species to the variety, from the variety to the race, and from the latter to a new species which appears only to disappear in its turn. It is only an affair of time. The living kingdom is in perpetual transformation. No one can tell what it will become naturally.
Such is the essence of the Darwinian theory. It begins by the hypothesis of a natural selection which no direct fact proves or confirms. But can the method of selection as Darwin explains it be the foundation of such a hypothesis? But in this artificial election, due to the labor of man, man is the agent who chooses, who works; he becomes the final and active cause of the transformation undergone by the species; he takes care that the character of the races which he has obtained should be maintained by an ever-vigilant election. Can anything of this kind be invoked in the natural selection of Darwin? Who replaces the choice of man? If the natural selection is made according to a plan decreed and premeditated by the omnipotence which has created nature, this selection changes its character; it is no longer anything but one of the forms of creation; it is an interpretation of the mode of acting of the creating cause, it is no longer the negation of this cause. Darwinism, which consists in conceiving the order of things without any superior intervention, under the simple action of accidents passing fortuitously to permanence; Darwinism, hostile to all finality, disappears if the idea of plan is perceptible in the natural selection. Can vital concurrence replace the intelligent action, and assure to the natural selection that fecundity and power which are not in it, and which must come to it from without? But can "vital concurrence, the battle of life," be the means of creation; can they engender directly organic modifications, varieties, animal species? Evidently not the battle of life can make subjects; it is an agent of elimination for weak and defective species; it cannot produce by itself a new species. Natural selection remains always delivered up to itself, to its blind resources, which nothing directs or regulates, which acquire fecundity only by chance. To imagine that the harmonic and infinite collection of living species can be legitimately referred to a given agent, even by granting to it thousands of years to manifest its action, seems to me arbitrary and sterile rashness, which has nothing in common with a noble rashness of science, with the intuitions of a genius which sometimes forestalls experience and the proofs which it adduces.
M. Janet has given a general refutation of the theories of Darwin, and sufficiently strong to show their folly. General facts have their own light, but it does not shine the less far or the less brilliantly for being general. Nevertheless, in a question obscured by so many prejudices, and by the assertions of a science which calls itself entirely experimental, that is to say, entirely particular, particular facts acquire a singular eloquence and power of demonstration which the most audacious systematizers cannot refuse to acknowledge.
Those facts embrace the infinite individualities of the living kingdom continued across the known ages. The source of information is inexhaustible. What does it teach us? Do particular facts confirm the ideas of Darwin regarding the gradual mutability of species; do they even furnish the sketch of a demonstration limited to certain determined points, to certain animal or vegetable species; do they finally show us some of those transformations which are the foundation of the system? Man has been observing and studying nature for centuries: tradition, the ruins preserved from the past, permit us to remount far up the stream of time; have they apprehended in nature any traces of those great changes which incessantly and fatally transform the vegetable and animal species? Or, on the contrary, does not everything go against those supposed transformations, and prove the fixity in time and space of those real species; a fixity which is not contradictory, which rather adapts itself to a certain normal physiological variability, which always allows to subsist and be perceptible through it the type of the species, the essential and primary form? We easily conceive the importance that a sincere response to these questions may acquire. They strike at the experimental foundation of Darwin's theory; if this experimental basis is wanting, what becomes of those theories? Are they not mere personal and arbitrary conceptions; brilliant plays of an imagination strong and creative, it is true, but which cannot be substituted for Nature herself and her direct teachings?
A learned professor of the faculty of science of Lyons, M. Ernest Faivre, has just undertaken this particular and experimental study of the origin of species, of their variability and essentiality; and we signalize his work to our readers—La Variabilité des Espèces et les Limites. It is impossible to write, on so complex and obscure a question, a book more rich in facts, more clear in its developments, or more authoritative in its conclusions. It seems to us the condemnation without appeal of the system of Darwin.
The vegetable kingdom is considered less rebellious than the others to the theories of Darwin; variety has more extended limits in it, less fixed than in the animal; generation, increase, the exterior conditions, present the occasion of many changes often profound in appearance. M. Faivre shows that the true species exists through all these changes, and that it is reproduced of itself from modified types, when circumstances or the artificial selection of man no longer supports the latter. Nowhere has man been able to create a real and durable species; and the species from the most remote times to our days are maintained with a fixity which has become one of the essential characters of species. The ancient land of Egypt is full of moving revelations on this subject: the animals, the plants, the grains buried in the caves, are the same as the plants and animals which cover the borders of the Nile at the present time. All the naturalists have proved this identity of a considerable quantity of animal and vegetable species. Hence, Lamarck and Darwin, to lessen the value of an experience of more than three thousand years' duration, have pretended that the conditions of life and the conditions of the exterior medium had not changed in Egypt from the historical times, and that the permanency of the species became consequently an ordinary and logical fact. But history, geography, the study of the soil, prove that the situation of Egypt has been profoundly modified. The level of the Nile, the limits of the desert, the extent of the cultivated lands, the culture of the soil, the number of populous cities, the proximity or distance of the sea, the great public works, everything which transforms a country under the action of men, all have changed in Egypt as much if not more than in other countries, and nothing is found changed in the productions of this soil, in the living beings which it supports and nourishes. But we may go further than the historical period. The permanence of species is proved to-day from the glacial period; the bogs of Ireland, the submarine forests of England and of the United States, conceal in their depths relics of mammifera or of vegetable species exactly comparable to the vegetable and animal species actually living in those same countries. We could not enumerate all the proofs which establish the great fact of the permanency of species; the number of these proofs is immense, and no fact seriously contradicts them, and yet it is in the name of experience that the partisans of natural selection pretend to speak! The accidental, temporary, and superficial varieties which they produce become for them a sufficient warrant of absolute and permanent varieties which they cannot produce, but of which they impudently suppose the formal existence; thus destroying species by a mere hypothesis.