Etienne Geoffroy St. Hilaire - Medical Library

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.”