Scientific observation tell us that living birds form a group or class
of animals, through which a certain form of skeleton runs; and that this
kind of skeleton differs in certain well-defined characters from that of
mammals. On the other hand, if anyone utterly ignorant of osteology, but
endowed with the artistic sense of form, were set before a bird skeleton
and a mammalian skeleton, he would at once see that the two were
similar and yet different. Very likely he would be unable to give
clear expression to his just sense of the differences and resemblances;
perhaps he would make great mistakes in detail if he tried.
Nevertheless, he would be able to draw from memory a couple of sketches,
in which all the salient points of likeness and unlikeness would be
reproduced with sufficient accuracy. The mere osteologist, however
accurately he might put the resemblances and differences into words,
if he lacked the artistic visualising faculty, might be hopelessly
incompetent to perform any such feat; lost in details, it might not even
occur to him that it was possible; or, still more probably, the habit of
looking for differences might impair the perception of resemblances.
Under these circumstances, the artist might be led to higher and broader
views, and thus be more useful to the progress of science than the
osteological expert. Not that the former attains the higher truth by a
different method; for the way of reaching truth is one and indivisible.
Whether he knows it or not, the artist has made a generalization
from two sets of facts, which is perfectly scientific in form;
and trustworthy so far as it rests upon the direct perception of
similarities and dissimilarities. The only peculiarity of the artistic
application of scientific method lies in the artist's power of
visualizing the result of his mental processes, of embodying the facts
of resemblance in a visible "type," and of showing the manner in which
the differences may be represented as modifications of that type;
he does, in fact, instinctively, what an architect, who desires to
demonstrate the community of plan in certain ancient temples, does by
the methodical construction of plans, sections, and elevations; the
comparison of which will furnish him with the "type" of such temples.
Thus, what I may term the artistic fashion of dealing with anatomy is
not only perfectly legitimate, but has been of great utility. The harm
of it does not begin until tine attempt is made to get more out of this
visual projection of thought than it contains; until the origin of the
notion of "type" is forgotten and the speculative philosopher deludes
himself with the supposition that the generalization suggested by fact
is an "Idea" of the Pure Reason, with which fact must, somehow or other,
be made to agree.