Internalism and Laws of Form 317
pleased the Creator to frame certain of his living creatures, there remains only the
alternative that the organic atoms have concurred fortuitously to produce such
harmony. But from this Epicurean slough of despond every healthy mind naturally
recoils" (1849, p. 40).
Owen chooses the formalist exit from Bunyan's swamp, and calls upon the
guidance of Plato to pull him out (an even classier assist than Dante's employment
of Virgil). Special homology can only be resolved by recognizing the common
generating pattern for all specific manifestations—the Platonic archetype (or
general homology) behind the variety of worldly incarnations. The archetype does
not denote an object or an ancestor, but an abstract generating formula, a blueprint,
and a formal cause. Owen engraved his version of the vertebrate archetype upon a
seal and wrote to his sister Maria in 1852, trying to explain this arcane concept in
layperson's terms: "It represents the archetype, or primal pattern—what Plato
would have called the 'divine idea' on which the osseous frame of all vertebrate
animals—i.e. all animals that have bones—has been constructed. The motto is 'the
one in the manifold,' expressive of the unity of plan which may be traced through
all the modifications of the pattern, by which it is adapted to the very habits and
modes of life of fishes, reptiles, birds, beasts, and human kind" (in Owen, 1894,
vol. 1, p. 388).
In 1849, Owen published his treatise, On the Nature of Limbs, originally
delivered as a lecture on February 9 at the Royal Institution. I regard this book as
the best expression of Owen's archetypal theory, the most interesting document
ever written in English to defend this strongest version of formalist theory in
biology.
Despite the title (aptly chosen and cleverly constructed as we shall see),
Owen's treatise attempts to reduce the entire vertebrate skeleton, in all its manifold
variety, to a single archetypal element, multiply repeated and specialized. Owen
writes: "General anatomical science reveals the unity which pervades the diversity,
and demonstrates the whole skeleton of man to be the harmonized sum of a series
of essentially similar segments, although each segment differs from the other, and
all vary from their archetype" (1849, p. 119).
For the naming and essence of this archetypal element, Owen agrees with
Geoffroy in designating the vertebra. We must conceptualize Owen's "vertebra"
not only as a spinal disc, but as a set of highly generalized elements (a central disc
surrounded by various bars and rods) ripe for modification along myriad pathways.
Owen's archetypal unit (Fig. 4-13) operates as an abstract blueprint of bursting
potential. (For example, in the "vertebra" that makes the shoulder girdle, the
pleurapophysis lateral to the centrum becomes the scapula, while the
haemapophysis below forms the coracoid, and the lowermost haemal spine makes
the front of the sternum.) Owen writes: "I have satisfactorily demonstrated that a
vertebra is a natural group of bones, that it may be recognized as a primary
division or segment of the endoskeleton, and that the parts of that group are
definable and recognizable under all their teleological modifications, their essential
relations and characters appearing