istory-method:" not only referring to
it in his preface, but in his first chapter giving examples of botanical
and zoological classifications, as illustrating the mode in which he
proposes to deal with the emotions. This we conceive to be a
philosophical conception; and we have only to regret that Mr. Bain has
overlooked some of its most important implications. For in what has
essentially consisted the progress of natural-history-classification? In
the abandonment of grouping by external, conspicuous characters; and in
the making of certain internal, but all-essential characters, the bases
of groups. Whales are not now ranged along with fish, because in their
general forms and habits of life they resemble fish; but they are
ranged with mammals, because the type of their organization, as
ascertained by dissection, corresponds with that of mammals. No longer
considered as sea-weeds in virtue of their forms and modes of growth,
_Polyzoa_ are now shown, by examination of their economy, to belong to
the animal kingdom. It is found, then, that the discovery of real
relationships involves analysis. It has turned out that the earlier
classifications, guided by general resemblances, though containing much
truth, and though very useful provisionally, were yet in many cases
radically wrong; and that the true affinities of organisms, and the true
homologies of their parts, are to be made out only by examining their
hidden structures. Another fact of great significance in the history of
classification is also to be noted. Very frequently the kinship of an
organism cannot be made out even by exhaustive analysis, if that
analysis is confined to the adult structure. In many cases it is needful
to examine the structure in its earlier stages; and even in its
embryonic stage. So difficult was it, for instance, to determine the
true position of the _Cirrhipedia_ among animals, by examining mature
individuals only, that Cuvier erroneously classed them with _Mollusca_,
even after dissecting them; and not until their early forms were
discovered, were they clearly proved to belong to the _Crustacea_. So
important, indeed, is the study of development as a means to
classification, that the first zoologists now hold it to be the only
absolute criterion.

Here, then, in the advance of natural-history-classification, are two
fundamental facts, which should be borne in mind when classifying the
emotions. If, as Mr. Bain rightly assumes, the emotions