thoughts which, whether we detect them or not, are expressed in
Nature,--then Nature is the work of thought, the production of
intelligence carried out according to plan, therefore premeditated,--and
in our study of natural objects we are approaching the thoughts of the
Creator, reading His conceptions, interpreting a system that is His and
not ours.

All the divergence from the simplicity and grandeur of this division of
the animal kingdom arises from an inability to distinguish between a plan
and the execution, of a plan. We allow the details to shut out the plan
itself, which exists quite independent of special forms. I hope we shall
find a meaning in all these plans that will prove them to be the parts of
one great conception and the work of one Mind.


II.

Proceeding upon the view that there is a close analogy between the way in
which every individual student penetrates into Nature and the progress of
science as a whole in the history of humanity, I continue my sketch of the
successive steps that have led to our present state of knowledge. I began
with Aristotle, and showed that this great philosopher, though he prepared
a digest of all the knowledge belonging to his time, yet did not feel the
necessity of any system or of any scientific language differing from the
common mode of expression of his day. He presents his information as a man
with his eyes open narrates in a familiar style what he sees. As
civilization spread and science had its representatives in other countries
besides Greece, it became indispensable to have a common scientific
language, a technical nomenclature, combining many objects under common
names, and enabling every naturalist to express the results of his