Your correspondent ‘Xn’ will find both his pleasure and his profit in reading the chapter on Instinct in ‘Darwin’s Origin of Species.’ It will give him some idea, I say not, how the reasoning faculty was first acquired, but how it may have been gradually developed. By a careful study of the same work he, and many others who need the knowledge, will see that in accordance with Darwinism the deterioration of a species is quite possible. His quaintly expressed argument about Adam’s ‘immediate progenitor’ omits to notice that in the moral world it is a step upward to become capable of sinning, just as in the physical world it is a step upward to become capable of dying, so that the wretchedest man with reason is higher in the scale than the noblest dog, and the humblest plant than the costliest and most beautiful stone. The other difficulty which he puts forward of an abrupt transition between the first man with reason and the parents of such a man without reason is a difficulty, like that in regard to the first vertebrate, one of words rather than of facts. As with the origin of language and of languages, as with the origin of the natural kingdoms and of every individual form of life, so with the origin of reason; could we see the whole series of steps, with their infinitely numerous and sometimes almost infinitely fine and subtle points of discrimination, we should probably be unable to fix upon any one definite division and say, here noise ends and articulate language begins; or, here Saxon ends and English begins; or, _this_ is the top of instinct, and _this_ the dawn of reason. OYSTERS OF THE CHALK, AND THE THEORY OF DEVELOPMENT.[65]