1908.

[67] _Recherches_, i., p. 81.

[68] _Regne Animal_, i., p. 91.

[69] _Ossemens Fossiles_, i., p. 26.

CHAPTER IV

GOETHE

Science, in so far as it rises above the mere accumulation of facts,
is a product of the mind's creative activity. Scientific theories are
not so much formulae extracted from experience as intuitions imposed
upon experience. So it was that Goethe, who was little more than a
dilettante,[70] seized upon the essential principles of a morphology
some years before that morphology was accepted by the workers.

Goethe is important in the history of morphological method because he
was the first to bring to clear consciousness and to express in
definite terms the idea on which comparative anatomy before him was
based, the idea of the unity of plan. We have seen that this idea was
familiar to Aristotle and that it was recognised implicitly by all who
after him studied structure comparatively. In Goethe's time the idea
had become ripe for expression. It was used as a guiding principle in
Goethe's youth particularly by Vicq d'Azyr and by Camper. The former
(1748-1794), who discovered[71] in the same year as Goethe (1784) the
intermaxillary bone in man, pointed out the homology in structure
between the fore limb and the hind limb, and interpreted certain
rudimentary bones, the intermaxillaries and rudimentary clavicles, in
the light of the theory that Vertebrates are built upon one single
plan of structure.

"Nature seems to operate always according to an original and general
plan, from which she departs with regret and whose traces we come
across everywhere" (Vicq d'Azyr, quoted by Flourens, _Mem. Acad.
Sei._, XXIII., p. xxxvi.).

Peter Camper (1722-1789), we are told by Goethe himself in his
_Osteologie_, was convinced of the unity of plan holding throughout
Vertebrates; he compared in particular the brain of fishes with the
brain of man.

The idea of the unity of plan had not yet become limited and defined
as a strictly scientific theory; it was an idea common to philosophy,
to ordinary thought, and to anatomical science. We find it expressed
by Herder (who perhaps got it from Kant) in his _Ideen sur Philosophie
der Geschichte der Menschheit_ (1784), and it is possible that Goethe
became impressed with the importance of the idea through his
conversations with Herder. Be that as it may, it is certain that
Goethe sought for the intermaxillaries in man only because h