We have reason to believe, as stated in the first chapter, that a change in the conditions of life, by specially acting on the reproductive system, causes or increases variability; and in the foregoing case the conditions of life are supposed to have undergone a change, and this would manifestly be favourable to natural selection, by giving a better chance of profitable variations occurring; and unless profitable variations do occur, natural selection can do nothing.
It may be said that natural selection is daily and hourly scrutinising, throughout the world, every variation, even the slightest; rejecting that which is bad, preserving and adding up all that is good; silently and insensibly working, whenever and wherever opportunity offers, at the improvement of each organic being in relation to its organic and inorganic conditions of life.
Chemistry is that branch of natural
philosophy in which the greatest improvements have been and may be made; it is on that account that I have made it my peculiar study; but at the same time, I have not neglected the other branches of science.
100] When he thought of men and women, it was of men and women as in the presence and under the influence of those effective natural objects, and linked to them by many associations.
Religious sentiment, consecrating the natural affections and rights of the human heart, above all that pitiful care and awe for the perishing human clay of which relic-worship is but the corruption, has always had much to do with localities, with the thoughts which attach themselves to definite scenes and places.
The smallness of the army renders the natural strength of the community an overmatch for it; and the citizens, not habituated to look up to the military power for protection, or to submit to its oppressions, neither love nor fear the soldiery; they view them with a spirit of jealous acquiescence in a necessary evil, and stand ready to resist a power which they suppose may be exerted to the prejudice of their rights.
This objection will be fully examined in its proper place, and it will be shown that the only natural precaution which could have been taken on this subject has been taken; and a much better one than is to be found in any constitution that has been heretofore framed in America, most of which contain no guard at all on this subject.
And the creation of health is the institution of a natural order and government of one by another in the parts of the body; and the creation of disease is the production of a state of things at variance with this natural order?
And is not the creation of justice the institution of a natural order and government of one by another in the parts of the soul, and the creation of injustice the production of a state of things at variance with the natural order?
An eternal future had always seemed natural
I shall have the pleasure of acknowledging the great assistance which I have received from several other naturalists, in the course of this and my other works; but I must be here allowed to return my most sincere thanks to the Reverend Professor Henslow, who, when I was an undergraduate at Cambridge, was one chief means of giving me a taste for Natural
History, -- who, during my absence, took charge of the collections I sent home, and by his correspondence directed my endeavours, -- and who, since my return, has constantly rendered me every assistance which the kindest friend could offer.