viously or with too much
difficulty. Nothing is worth doing or well done which is not done fairly
easily, and some little deficiency of effort is more pardonable than any
very perceptible excess; for virtue has ever erred rather on the side of
self-indulgence than of asceticism, and well-being has ever advanced
through the pleasures rather than through austerity.

According to Buffon, then--as also according to Dr. Darwin, who was just
such another practical and genial thinker, and who was distinctly a
pupil of Buffon, though a most intelligent and original one--if an organ
after a reasonable amount of inspection appeared to be useless, it was
to be called useless without more ado, and theories were to be ordered
out of court if they were troublesome. In like manner, if animals bred
freely _inter se_ before our eyes, as for example the horse and ass, the
fact was to be noted, but no animals were to be classed as capable of
interbreeding until they had asserted their right to such classification
by breeding with tolerable certainty. If, again, an animal looked as if
it felt, that is to say, if it moved about pretty quickly or made a
noise, it must be held to feel; if it did neither of these things, it
did not look as if it felt and therefore it must be said not to feel.
_De non apparentibus et non existentibus eadem est lex_ was one of the
chief axioms of their philosophy; no writers have had a greater horror
of mystery or of ideas that have not become so mastered as to be, or to
have been, superficial. Lamarck was one of those men of whom I believe
it has been said that they have brain upon the brain. He had his theory
that an animal could not feel unless it had a nervous system, and at
least a spinal marrow--and that it could not think at all without a
brain--all his facts, therefore, have to be made to square with this.
With Buffon and Dr. Darwin we feel safe that however wrong they may
sometimes be, their conclusions have always been arrived at on that
fairly superficial view of things in which, as I have elsewhere said,
our nature alone permits us to be comforted.

To these writers, then, the doctrine of final causes for rudimentary
organs was a piece of mystification and an absurdity; no less fatal to
any such doctrine were the processes of embryological development. It
was plain that the commonly received teleology must be given up; but the
idea of design or purpose was so associated in their minds with
theologic