《天演论》的原名为“Evolution and Ethics and other Assays”，也即是《进化与伦理》。中译本在辛亥革命前出版。
It may be safely assumed that, two thousand years ago, before Caesar set foot in southern Britain, the whole countryside visible from the windows of the room in which I write, was in what is called "the state of nature". Except, it may be, by raising a few sepulchral mounds, such as those which still, here and there, break the flowing contours of the downs, man's hands had made on mark upon it; and the thin veil of vegetation which overspread the broad-backed heights and the shelving sides of the coombs was unaffected by his industry. The nature grasses and weeds, the scattered patches of gores contended with one another for the possession of the scanty surface soil; they fought against the droughts of summer, the frosts of winter, and the furious gales which swept, with unbroken force, now from the Atlantic, and now from the North Sea, at all times of the year; they filled up, as they might, the gaps made in their ranks by all sorts of underground animal ravagers. One year after another, with an average population, the floating balance of the unceasing struggle for existence among the indigenous plants, maintained itself.