Herbert Spencer

“ A little careful introspection will show them that they have never yet realized to themselves the creation of even one species. If they have formed a definite conception of the process, they will be able to answer such questions as — How is a new species constructed? and How does it make its appearance? Is it thrown down from the clouds? or must we hold to the notion that it struggles up out of the ground? ”

“ A tree differs from a seed immeasurably in every respect — in bulk, in structure, in colour, in form, in specific gravity, in chemical composition; differs so greatly that no visible resemblance of any kind can be pointed out between them. ”

“ Habitually looking at things rather in their statical than in their dynamical aspect, they never realize the fact that, by small increments of modification, any amount of modification may in time be generated. That surprise which they feel on finding one whom they last saw as a boy, grown into a man, becomes incredulity when the degree of change is greater. ”

“ That the uneducated and the ill-educated should think the hypothesis that all races of beings, man inclusive, may in process of time have been evolved from the simplest monad, a ludicrous one, is not to be wondered at. ”

“ Though, from the impossibility of getting at a sufficiency of facts, they are unable to trace the many phases through which any existing species has passed in arriving at its present form, or to identify the influences which caused the successive modifications, yet they can show that any existing species — animal or vegetable — when placed under conditions different from its previous ones, immediately begins to undergo certain changes of structure fitting it for the new conditions. ”

“ Thus, if a cone be cut by a plane at right angles to its axis we get a circle. If, instead of being perfectly at right angles, the plane subtends with the axis an angle of 89° 59′, we have an ellipse which no human eye, even when aided by an accurate pair of compasses can distinguish from a circle. Decreasing the angle minute by minute the ellipse becomes first perceptibly eccentric, then manifestly so, and by and by acquires so immensely elongated a form, as to bear no recognizable resemblance to a circle. By continuing this process the ellipse passes insensibly into a parabola ”

“ But for the physiologist, who knows that every individual being is so evolved — who knows further, that in their earliest condition the germs of all plants and animals whatever are so similar, "that there is no appreciable distinction amongst them which would enable it to be determined whether a particular molecule is the germ of a conferva or an oak, of a zoophyte or of a man" — for him to make a difficulty of the matter is inexcusable. ”

“ What can be more widely contrasted than a newly-born child and the small, semi-transparent, gelatinous spherule constituting the human ovum? The infant is so complex in structure that a cyclopædia is needed to describe its constituent parts. ”

“ And thus they can show that throughout all organic nature there is at work a modifying influence of the kind they assign as the cause of these specific differences — an influence which, though slow in its action, does, in time, if the circumstances demand it, produce marked changes — an influence which, to all appearance, would produce in the millions of years, and under the great varieties of condition which geological records imply, any amount of change. ”

“ So far from its being unreasonable to ask so much of them, it would be reasonable to ask not only for a possible mode of special creation, but for an ascertained mode; seeing that this is no greater a demand than they make upon their opponents. ”

“ Should the believers in special creations consider it unfair thus to call upon them to describe how special creations take place, I reply, that this is far less than they demand from the supporters of the development hypothesis. ”

“ They can show, too, that the changes daily taking place in ourselves — the facility that attends long practice, and the loss of aptitude that begins when practice ceases — the strengthening of passions habitually gratified, and the weakening of those habitually curbed — the development of every faculty, bodily, moral, or intellectual, according to the use made of it — are all explicable on this same principle. ”

“ They can show that in successive generations these changes continue until ultimately the new conditions become the natural ones. They can show that in cultivated plants, in domesticated animals, and in the several races of men, these changes have uniformly taken place. They can show that the degrees of difference so produced are often, as in dogs, greater than those on which distinctions of species are in other cases founded. They can show that it is a matter of dispute whether some of these modified forms are varieties or separate species. ”

“ We have, indeed, in the part taken by many scientific men in this controversy of "Law versus Miracle," a good illustration of the tenacious vitality of superstitions. Ask one of our leading geologists or physiologists whether he believes in the Mosaic account of the creation, and he will take the question as next to an insult. ”

“ Even could the supporters of the development hypothesis merely show that the production of species by the process of modification is conceivable, they would be in a better position than their opponents. ”

“ Do its limbs and viscera rush together from all the points of the compass? or must we receive some such old Hebrew notion as, that God goes into a forest-cavern, and there takes clay and moulds a new creature? If they say that a new creature is produced in none of these modes, which are too absurd to be believed, then they are required to describe the mode in which a new creature may be produced — a mode which does not seem absurd ”