he suspects that any sensitive nerve may be rendered sensitive to light, and likewise to those coarser vibrations of the air which produce sound.—p-187.
And in the following passage he carries this extravagance to the highest pitch, requiring a licence for advancing as true any theory which cannot be demonstrated to be actually impossible:—
If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down. But I can find no such case.—p. 189.
Another of these assumptions is not a little remarkable. It suits his argument to deduce all our known varieties of pigeons from the rock-pigeon (the Columba livia), and this parentage is traced out, though not, we think, to demonstration, yet with great ingenuity and patience. But another branch of the argument would be greatly strengthened by establishing the descent of our various breeds of dogs with their perfect power of fertile inter-breeding from different natural species. And accordingly, though every fact as to the canine race is parallel to the facts which have been used before to establish the common parentage of the pigeons in Columba livia, all these are thrown over in a moment, and Mr. Darwin, first assuming, without the shadow of proof, that our domestic breeds are descended from different species, proceeds calmly to argue from this, as though it were a demonstrated certainty.
It seems to me unlikely in the case of the dog-genus, which is distributed in a wild state throughout the world, that since man first appeared one species alone should have been domesticated.—p. 18.
In some cases I do not doubt that the intercrossing of species
aboriginally distinct has played an important part in the origin of
our domestic productions.—p. 43.
What new words are these for a loyal disciple of the true Baconian philosophy?—"I can conceive"—"It is not incredible"—"I do not doubt" —"It is conceivable."
For myself, I venture confidently to look back thousands on thousands of generations, and I see an animal striped like a zebra, but perhaps otherwise very differently constructed, the common parent of our domestic horse, whether or not it be descended from one or more wild stocks of the ass, hemionous, quagga, or zebra.—p. 167.
In the name of all true philosophy we protest against such a mode of dealing with nature, as utterly dishonourable to all natural science, as reducing it from its present lofty level of being one of the noblest trainers of man's intellect and instructors of his mind, to being a mere idle play of the fancy, without the basis of fact or the discipline of observation. In the "Arabian Nights" we are not offended as at an impossibility when Amina sprinkles her husband with water and transforms him into a dog, but we cannot open the august doors of the venerable temple of scientific truth to the genii and magicians of romance. We plead guilty to Mr. Darwin's imputation that
the chief cause of our natural unwillingness to admit that one species has given birth to other and distinct species is that we are always slow in admitting any great change of which we do not see the intermediate steps.—p. 481.