are to be
grouped after the natural-history-method; then it should be the
natural-history-method in its complete form, and not in its rude form.
Mr. Bain will doubtless agree in the belief, that a correct account of
the emotions in their natures and relations, must correspond with a
correct account of the nervous system--must form another side of the
same ultimate facts. Structure and function must necessarily harmonize.
Structures which have with each other certain ultimate connexions, must
have functions which have answering connexions. Structures which have
arisen in certain ways, must have functions which have arisen in
parallel ways. And hence if analysis and development are needful for the
right interpretation of structures, they must be needful for the right
interpretation of functions. Just as a scientific description of the
digestive organs must include not only their obvious forms and
connexions, but their microscopic characters, and also the ways in which
they severally result by differentiation from the primitive mucous
membrane; so must a scientific account of the nervous system include its
general arrangements, its minute structure, and its mode of evolution;
and so must a scientific account of nervous actions include the
answering three elements. Alike in classing separate organisms, and
in classing the parts of the same organism, the complete
natural-history-method involves ultimate analysis, aided by development;
and Mr. Bain, in not basing his classification of the emotions on
characters reached through these aids, has fallen short of the
conception with which he set out.

"But," it will perhaps be asked, "how are the emotions to be analyzed,
and their modes of evolution to be ascertained? Different animals, and
different organs of the same animal, may readily be compared in their
internal structures and microscopic structures, as also in their
developments; but functions, and especially such functions as the
emotions, do not admit of like comparisons."

It must be admitted that the application of these methods is here by no
means so easy. Though we can note differences and similarities between
the internal formations of two animals; it is difficult to contrast the
mental states of two animals. Though the true morphological relations of
organs may be made out by observation of embryos; yet, where such organs
are inactive before birth, we cannot completely trace the history of
their actions. Obviousl