, and thus predicate the general of the
individual, and class the individual under the general. This is the secret
of all scientific knowledge. Many sciences, while passing through this
second or classificatory stage, assume the title of comparative. When the
anatomist has finished the dissection of numerous bodies, when he has
given names to each organ, and discovered the distinctive functions of
each, he is led to perceive similarity where at first he saw dissimilarity
only. He discovers in the lower animals rudimentary indications of the
more perfect organization of the higher; and he becomes impressed with the
conviction that there is in the animal kingdom the same order and purpose
which pervades the endless variety of plants or any other realm of nature.
He learns, if he did not know it before, that things were not created at
random or in a lump, but that there is a scale which leads, by
imperceptible degrees, from the lowest infusoria to the crowning work of
nature,--man; that all is the manifestation of one and the same unbroken
chain of creative thought, the work of one and the same all-wise Creator.

In this way the second or classificatory leads us naturally to the third
or final stage--the theoretical, or metaphysical. If the work of
classification is properly carried out, it teaches us that nothing exists
in nature by accident; that each individual belongs to a species, each
species to a genus; and that there are laws which underlie the apparent
freedom and variety of all created things. These laws indicate to us the
presence of a purpose in the mind of the Creator; and whereas the material
world was looked upon by ancient philosophers as a mere illusion, as an
agglomerate of atoms, or as the work of an evil principle, we now read and
interpret its pages as the revelation of a divine power, and wisdom, and
love. This has given to the study of nature a new character. After the
observer has collected his facts, and after the classifier has placed them
in order, the student asks what is the origin and what is the meaning of
all this? and he tries to soar, by means of induction, or sometimes even
of divination, into regions not accessible to the mere collector. In this
attempt the mind of man no doubt has frequently met with the fate of
Phaeton; but, undismayed by failure, he asks again and again for his
father's steeds. It has been said that this so-called philosophy of nature
has never achieved anything; that i