|Etienne Geoffroy St. Hilaire, Principes
de Philosophie Zoologique (Paris, 1830).
In the early 18th century, the Natural Theological views of
Linnaeus and Paley receded to the background of the scientific
debates, leaving behind its core principle of Universality.
In debates with his greatest rival, Georges Cuvier over the
proper interpretation of anatomical structures in Zoology, St.-Hilaire
defended the terms Unity of Plan and Unity of Composition against
critiques that they were pantheistic. For St-Hilaire:
“The universality of the principle of the Unity of Organization
is a necessary fact. And indeed if one considers all the arrangements
of the universe at their principle, one finds a very small number
of materials, and also few, and restricted, forces that apply
to them--these forces are themselves only the simultaneous reciprocal
action of the properties of the elementary bodies.”