This is a strongly-marked case; but its features, although unusually prominent, are like those of the general run of the considerations by which evolution is supposed to exclude design.  Those of the penultimate citation and its context are all of the same stamp.  The differences which begin as variations are said to be spontaneous—­a metaphorical word of wide meanings—­are inferred to be casual (whereas we only know them to be occult), or to be originated by surrounding agencies (which is not in a just sense true); they are legitimately inferred to be led on by natural selection, wholly new structures or organs appear, no one can say how, certainly no one can show that they are necessary outcomes of what preceded; and these two are through natural selection kept in harmony with the surroundings, adapted to different ones, diversified, and perfected; purposes are all along subserved through exquisite adaptations; and yet the whole is thought to be undesigned, not because of any assigned reason why this or that must have been thus or so, but simply because they all occurred in Nature!  The Darwinian theory implies that the birth and development of a species are as natural as those of an individual, are facts of the same kind in a higher order.  The alleged proof of the absence of design from it amounts to a simple reiteration of the statement, with particulars.  Now, the marks of contrivance in the structure of animals used not to be questioned because of their coming in the way of birth and development.  It is curious that a further extension of this birth and development should be held to disprove them.  It appears to us that all this is begging the question against design in Nature, instead of proving that it may be dispensed with.

Two things have helped on this confusion.  One is the notion of the direct and independent creation of species, with only an ideal connection between them, to question which was thought to question the principle of design.  The other is a wrong idea of the nature and province of natural selection.  In former papers we have over and over explained the Darwinian doctrine in this respect.  It may be briefly illustrated thus:  Natural selection is not the wind which propels the vessel, but the rudder which, by friction, now on this side and now on that, shapes the course.  The rudder acts while the vessel is in motion, effects nothing when it is at rest.  Variation answers to the wind:  “Thou hearest the sound thereof, but canst not tell when it cometh and whither it goeth.”  Its course is controlled by natural selection, the action of which, at any given moment, is seemingly small or insensible; but the ultimate results are great.  This proceeds mainly through outward influences.  But we are more and more convinced that variation, and therefore the ground of adaptation, is not a product of, but a response to, the action of the environment.  Variations, in other words, the differences between individual plants and animals, however originated, are evidently not from without but from within—­not physical but physiological.