which is very much the Napoleonic
doctrine, that Providence favors the strongest battalions,--that,
since many more individuals are born than can possibly survive, those
individuals and those variations which possess any advantage, however
slight, over the rest, are in the long run sure to survive, to
propagate, and to occupy the limited field, to the exclusion or
destruction of the weaker brethren. All this we pondered, and could
not much object to. In fact, we began to contract a liking for a
system which at the outset illustrates the advantages of good
breeding, and which makes the most "of every creature's best."

Could we "let by-gones be by-gones," and, beginning now, go
on improving and diversifying for the future by natural
selection,--could we even take up the theory at the introduction of the
actually existing species, we should be well content, and so perhaps would
most naturalists be. It is by no means difficult to believe that
varieties are incipient or possible species, when we see what trouble
naturalists, especially botanists, have to distinguish between
them,--one regarding as a true species what another regards as a
variety; when the progress of knowledge increases, rather than
diminishes, the number of doubtful instances; and when there is less
agreement than ever among naturalists as to what the basis is in
Nature upon which our idea of species reposes, or how the word is
practically to be defined. Indeed, when we consider the endless
disputes of naturalists and ethnologists over the human races, as to
whether they belong to one species or to more, and if to more,
whether to three, or five, or fifty, we can hardly help fancying that
both may be right,--or rather, that the uni-humanitarians would have
been right several thousand years ago, and the multi-humanitarians
will be a few thousand years later; while at present the safe thing
to say is, that, probably, there is some truth on both sides.
"Natural selection," Darwin remarks, "leads to divergence of
character; for more living brings can be supported on the same area
the more they diverge in structure, habits, and constitution," (a
principle which, by the way, is paralleled and illustrated by the
diversification of human labor,) and also leads to much extinction of
intermediate or unimproved forms. Now, though this divergence may
"steadily tend to increase," yet this is evidently a slow process in
Nature, and liable to much counteraction wherever