If the brutes have consciousness and no souls, then it is clear that, in them, consciousness is a direct function of material changes; while, if they… - Thomas Henry Huxley

History warns us, however, that it is the customary fate of new truths to begin as heresies and to end as superstitions; and, as matters now stand, it is hardly rash to anticipate that, in another twenty years, the new generation, educated under the influences of the present day, will be in danger of accepting the main doctrines of the 'Origin of Species' with as little reflection, and it may be with as little justification, as so many of our contemporaries, twenty years ago, rejected them. Against any such a consummation let us all devoutly pray; for the scientific spirit is of more value than its products, and irrationally held truths may be more harmful than reasoned errors.

Our reverence for the nobility of manhood will not be lessened by the knowledge, that Man, is in substance and in structure, one with the brutes; for, he alone possesses the marvellous endowment of intelligible and rational speech, whereby, in the secular period of his existence, he has slowly accumulated and organized the experience which is almost wholly lost with the cessation of every individual life in other animals; so that now he stands raised upon it as on a mountain top, far above the level of his humble fellows, and transfigured from his grosser nature by reflecting, here and there, a ray from the infinite source of truth.

Regarded anatomically, the resemblances between the foot of Man and the foot of the Gorilla are far more striking and important than the differences. ...be the differences between the hand and foot of Man and those of the Gorilla what they may—the differences between those of the Gorilla and those of the lower Apes are much greater.