Изображения страниц
PDF
EPUB

Variations, which by their gradual accumulation give rise to new species, genera, families, and orders, are themselves, step by step, accidental. Mr. Darwin sometimes says they happen by chance; sometimes he says they happen of necessity; at others he says, "We are profoundly ignorant of their causes." These are only different ways of saying that they are not intentional. When a man lets anything fall from his hands, and says it was accidental, he does not mean that it was causeless, he only means that it was not intentional. And that is precisely what Darwin means when he says that species arise out of accidental variations. His whole book is an argument against teleology. The whole question is, How are we to account for the innumerable varieties, kinds, and genera of plants and animals, including man? Were they intended? or, Did they arise from the gradual accumulations of unintentional variations? His answer to these questions is plain. On page 245, he says: "Nothing at first can appear more difficult to believe than that the more complex organs and instincts have been perfected not by means superior to, though analogous with, human reason, but by innumerable slight variations, each good

Nevertheless,

for the individual possessor. this difficulty, though appearing to our imagination1 insuperably great, cannot be considered real, if we admit the following propositions, namely, that all parts of the organizations and instincts offer, at least, individual differences; that there is a struggle for existence, which leads to the preservation of profitable deviations of structure or instinct; and, lastly, that gradations in the state of perfection of each organ may have existed, each good of its kind." He says, over and over, that if beauty or any variation of structure can be shown to be intended, it would "annihilate his theory." His doctrine is that such unintended variations, which happen to be useful in the struggle for life, are preserved, on the principle of the survival of the fittest. He urges the usual objections to teleology derived from undeveloped or useless organs, as web-feet in the upland goose and frigate-bird, which never swim.

What, however, perhaps more than anything, makes clear his rejection of design is the manner in which he deals with the complicated or

[ocr errors]

1 What can the word "6 imagination mean in this sentence, if it does not mean "Common Sense ?”

[ocr errors]

gans of plants and animals. Why don't he say, they are the product of the divine intelligence? If God made them, it makes no difference, so far as the question of design is concerned, how He made them: whether at once or by a process of evolution. But instead of referring them to the purpose of God, he laboriously endeavors to prove that they may be accounted for without any design or purpose whatever.

[ocr errors]

"To suppose," he says, "that the eye with all its inimitable contrivances for adjusting the focus to different distances, for admitting different degrees of light, and for the correction of spherical and chromatic aberration, could have been formed by natural selection, seems, I freely confess, absurd in the highest degree. (p. 222) Nevertheless he attempts to explain the process. "It is scarcely possible," he says, "to avoid comparing the eye with the telescope. We know that this instrument has been perfected by the long continued efforts of the highest of human intellects; and we naturally infer that the eye has been formed by a somewhat analogous process. But may not this inference be presumptuous? Have we any right to assume that the Creator works by intellectual powers like those of man? If we must compare

the eye to an optical instrument, we ought in imagination to take a thick layer of transparent tissue, with spaces filled with fluid, and with a nerve sensitive to light beneath, and then suppose every part of this layer to be continually changing slowly in density, so as to separate into layers of different densities and thicknesses, placed at different distances from each other, and with the surfaces of each layer slowly changing in form. Further, we must suppose that there is a power represented by natural selection, or the survival of the fittest, always intently watching each slight alteration in the transparent layers, and carefully preserving each, which, under varied circumstances, tends to produce a distinct image. We must suppose each new state of the instrument to be multiplied by the million; each to be preserved until a better is produced, and the old ones to be all destroyed. In living bodies, variations will cause the slight alterations, generation will multiply them almost infinitely, and natural selection will pick out with unerring skill each improvement." (p. 226)

"Let this process,

1 Mr. Darwin's habit of personifying nature has given, as his friend Mr. Wallace says, his readers a good deal of trouble. He defines nature to be the aggregate of physical forces; and in

he says,

[ocr errors]

go on for millions of years," and we shall at last have a perfect eye.

It would be absurd to say anything disrespectful of such a man as Mr. Darwin, and scarcely less absurd to indulge in any mere extravagance of language; yet we are expressing our own experience, when we say that we regard Mr. Darwin's books the best refutation of Mr. Darwin's theory. He constantly shuts us up to the alternative of believing that the eye is a work of design or the product of the unintended action of blind physical causes. To any ordinarily constituted mind, it is absolutely impossible to believe that it is not a work of design. Darwin himself, it is evident, dear as his theory is, can hardly believe it. "It is indispensable," he says, "to arrive at a just conclusion as to the formation of the eye, that the reason should conquer the imagination; but I have felt the difficulty far too keenly to be surprised at any degree of hesitation in extending the principle of natural selection to so startling an extent." (p. 225)

the single passage quoted, he speaks of Natural Selection "as intently watching ""picking out with unerring skill," and "carefully preserving." It is true, 'he tells us this is all to be understood metaphorically.

« ПредыдущаяПродолжить »