PROGRESS or OKNITHOEOGICAL SCIENCE. 193 
*ary to view it in two positions ; firsts in regard to the 
principles upon which it is prosecuted, and secondly, 
how far tlicse principles have been apphed to practical 
use, or in other words, to the clear determination of the 
species. The first of these views contemplates ornitho. 
logy as an inductive science, and its rank in the scale of 
human knowledge will be determined by the greater or 
lesser accordance of its fumlamental principles with those 
which regulate every other branch of the physical sciences, 
— by the simplification and reduction of its innumera- 
ble facts to a few universal laws — and by the analogy 
which can be traced lietween these laws, and such others 
that have been detennined in higher and more extended 
portions of creation. For although the study of this 
branch of zoology is so vast, compared to our limited 
faculties, that an ordinary life would hardly be sufficient 
for thoroughly understanding it, yet it is but a very 
small point in the circle of the physical sciences, which 
embraces all matter ami all creation. When, there- 
fore, we have advanced in the philosophy of any branch 
of natural history, so far as to assimilate its laws 
with others that have been determined in conterminous 
branches, we have demonstrative evidence tliat our as- 
sumptions are correct ; but if two or three of these laws 
can be stiff farther traced throughout the visible creation, 
and even to extend themselves to aU that is known of 
the spiritual world, our evidence is of a much higher 
cast. Tile truths of the one, become not only connected, 
but, as it were, amalgmated, with the truths of the other; 
they cannot, in minds accustomed to inductive reasoning, 
be separated ; and we become as much inclined to ques- 
tion the circular progress of the planets round the sun, 
as tile circular development of the variation of forms in 
the animal and the vegetable creation. 
(166.) Ornithology, no less than other branches of 
zoology, is rapidly approaching, in its fundamental prin- 
ciples, to the state of demonstrative certainty just inti- 
rngted. Enough has been already published to show 
that the principles upon which it is now founded, as a 
o 
