What do our up-to-date scientists think (if they think at all) of the justification of vivisection put forward by Monsignor John S. Vaughan, a sacerdotalist of the medieval school? To a watchful observer few things could have been more entertaining than the spectacle of an old-world Catholic, a belated casuist of (say) thirteenth century temperament, coming forward in the _Saturday Review_ (new style) to justify, from a moral standpoint, the doings of the modern vivisector, and basing his argument on the immemorial “proposition” that “beasts exist for the use and benefit of man.” Now, there are undoubtedly numbers of persons living in this twentieth century who still hold the belief that the animals were created for man’s pleasure, and it may be that, in appealing to that ancient superstition, Mgr. Vaughan was using the most popular weapon in the pro-vivisectionist armoury. But whatever the “man in the street” may think on this subject, the evolutionist and man of science, at any rate, is _not_ able to take refuge in the plea that man is the centre of the universe, and that all other beings were created for mankind; for if there is one thing above others that Darwin’s followers have scouted, it is this old anthropocentric notion which forms the Monsignor’s “proposition.” The animals, according to the scientific view, were not designed for man’s benefit, nor is there any impassable gulf between human and non-human--on the contrary, man was evolved from among the animals, and is in very truth an animal himself. This is the creed, beyond denial or evasion, of the Darwinian scientists, whose torture of their rudimentary brethren the sacerdotalist is so eager to condone. Monsignor Vaughan is defending vivisection by an assumption which the vivisectors themselves must hold to be unscientific and obsolete. The sufficient answer to the anthropocentric fallacy of the theologian is found in Mr. Howard Moore’s laconic remark: “But Darwin has lived.”