CHAPTER IV.

THEORY OF DEVELOPMENT ACCORDING TO GOETHE AND OKEN.

Scientific Insufficiency of all Conceptions of a Creation of Individual Species.—Necessity of the Counter Theories of Development.—Historical Survey of the most Important Theories of Development.—Aristotle.—His Doctrine of Spontaneous Generation.—The Meaning of Nature-philosophy.—Goethe.—His Merits as a Naturalist.—His Metamorphosis of Plants.—His Vertebral Theory of the Skull.—His Discovery of the Mid Jawbone in Man.—Goethe’s Interest in the Dispute between Cuvier and Geoffroy St. Hilaire.—Goethe’s Discovery of the two Organic Formative Principles, of the Conservative Principle of Specification (by Inheritance), and of the Progressive Principle of Transformation (by Adaptation).—Goethe’s Views of the Common Descent of all Vertebrate Animals, including Man.—Theory of Development according to Gottfried Reinhold Treviranus.—His Monistic Conception of Nature.—Oken.—His Nature-philosophy.—Oken’s Theory of Protoplasm.—Oken’s Theory of Infusoria (Cell Theory).—Oken’s Theory of Development 72