“... As all the living forms of life are the lineal descendants of those which lived long before the Silurian epoch, we may feel certain that the ordinary succession by generation has never once been broken, and that no cataclysm has desolated the whole world. Hence we may look with some confidence to a secure future of equally inappreciable length. And as natural selection works solely by and for the good of each being, all corporeal and mental endowments will tend to progress toward perfection.
It is interesting to contemplate an entangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent on each other in so complex a manner, have all been produced by laws acting around us. These laws, taken in the largest sense, being Growth with Reproduction; Variability from the indirect and direct action of the external conditions of life, and from use and disuse; a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction of less-improved forms. Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is a grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful hav been, and are being, evolved.”
Concluding paragraphs of The Origin of Species, 1859.
Retyping the above from my copy, I reflect that the sense of 'perfection' is rather specialised, and the sense of 'secure' as broad as it is possible to imagine. The use-and-disuse suggestion is not quite how it works, because genetics hadn't been discovered yet. 'Breathed' is an interesting choice; I think it is a courteous ambiguity, which probably worked for a lot of readers.
The central idea is as powerful, and the concluding sentence as magnificent, as it ever was.
[Update: Musical Protolanguage: Darwin's theory of language evolution revisited. I have wondered recently whether what your native language is has any predictable effect on how you hear the accents in a melody.]