; and the genera into subfamilies,
families and orders, all under one great class. The grand fact of the
natural subordination of organic beings in groups under groups, which,
from its familiarity, does not always sufficiently strike us, is in
my judgment thus explained. No doubt organic beings, like all other
objects, can be classed in many ways, either artificially by single
characters, or more naturally by a number of characters. We know,
for instance, that minerals and the elemental substances can be thus
arranged. In this case there is of course no relation to genealogical
succession, and no cause can at present be assigned for their falling
into groups. But with organic beings the case is different, and the view
above given accords with their natural arrangement in group under group;
and no other explanation has ever been attempted.

Naturalists, as we have seen, try to arrange the species, genera and
families in each class, on what is called the Natural System. But what
is meant by this system? Some authors look at it merely as a scheme for
arranging together those living objects which are most alike, and for
separating those which are most unlike; or as an artificial method of
enunciating, as briefly as possible, general propositions--that is,
by one sentence to give the characters common, for instance, to all
mammals, by another those common to all carnivora, by another those
common to the dog-genus, and then, by adding a single sentence, a full
description is given of each kind of dog. The ingenuity and utility of
this system are indisputable. But many naturalists think that something
more is meant by the Natural System; they believe that it reveals the
plan of the Creator; but unless it be specified whether order in time
or space, or both, or what else is meant by the plan of the Creator,
it seems to me that nothing is thus added to our knowledge. Expressions
such as that famous one by Linnaeus, which we often meet with in a more
or less concealed form, namely, that the characters do not make the
genus, but that the genus gives the characters, seem to imply that some
deeper bond is included in our classifications than mere resemblance.
I believe that this is the case, and that community of descent--the one
known cause of close similarity in organic beings--is the bond, which,
though observed by various degrees of modification, is partially
revealed to us by our classifications.

Let us now consider the rules