Philosophie anatomique

work by Geoffroy Saint-Hilaire

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July 1, 2026

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Philosophie anatomique is a two-volume work by French naturalist Étienne Geoffroy Saint-Hilaire, published between 1818 and 1822. In this work, Saint-Hilaire presented his studies on anatomy, particularly focusing on embryos. He proposed the principle of "unity of composition," suggesting that all animals share a fundamental, consistent structural plan. This principle became a cornerstone of comparative anatomy.

Saint-Hilaire also founded teratology, the study of animal malformations. His work laid important groundwork for evolutionary concepts, influencing later scientists like Charles Darwin. He believed that species could evolve through the occasional appearance of successful variations, a view that contrasted with Georges Cuvier's denial of evolution.1

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Étienne Geoffroy Saint-Hilaire
…he would later summarize in Philosophie anatomique, 2 vol. (1818–22). His studies on embryos supplied important evidence for his views on the unity of organic composition among vertebrates, which he now defined in three parts: the law of development, whereby no organ arises or disappears suddenly, explaining vestiges; the law…
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…he would later summarize in Philosophie anatomique, 2 vol. (1818–22). His studies on embryos supplied important evidence for his views on the unity of organic composition among vertebrates, which he now defined in three parts: the law of development, whereby no organ arises or disappears suddenly, explaining vestiges; the law…
Read More