and especially nineteenth-century biology, hinged upon this spread, Naturphilosophie must be counted as an influential movement in the history of science. As Louis Agassiz testifies:

The young naturalist of that day who did not share, in some degree, the intel- lectual stimulus given to scientific pursuits by physio-philosophy [Naturphilosophie⁶] would have missed a part of his training . . . The great merit of the physio-philosophers consisted in their suggestiveness. They did much in freeing our age from the low estimation of natural history as a science which prevailed in the last century. They stimulated a spirit of independence among observers; but they also instilled a spirit of daring, which, from its extravagance, has been fatal to the whole school, (in E. Agassiz, 1885, pp. 152–153)

Two Leading Recapitulationists among
the Naturphilosopheii: Oken and Meckel

Lorenz Oken's Lehrbuch der Naturphilosophie appeared in three parts from 1809–1811. It is a listing of 3,562 statements, taking all knowledge for its province, and filled with bald, oracular pronouncements of the engaging sort that feign profundity but dissolve into emptiness upon close inspection. It is also responsible for Oken's bad reputation as the most idle (if cosmic) speculator of a school rife with unreason.7 In fact, Oken was one of the best comparative anatomists and embryologists of his day; his works on the embryology of the pig and dog (1806) are classics (he was also an influential, if naive, political thinker of liberal to radical bent—see Raikov, 1969). Russell called him "a careful student of embryology" (1916, p. 90). Von Baer, an implacable foe of recapitulation and much else dear to Oken's system, wrote that his observations "are often among the most accurate that we possess about mammals, and the general statements, although a majority of them must now appear erroneous, have, nonetheless, infinitely furthered [unendlich gefördert] our knowledge of development" (1828, p. xvii). Louis Agassiz attended Oken's lectures and wrote:

Among the most fascinating of our professors was Oken. A master in the art of teaching, he exercised an almost irresistible influence over his students. Constructing the universe out of his own brain, deducing from a priori con- ceptions all the relations of the three kingdoms into which he divided all living beings, classifying the animals as if by magic, in accordance with an analogy based on the dismembered body of man, it seemed to us who listened that the slow laborious process of accumulating precise detailed knowledge could only be the work of drones, while a generous, commanding spirit might build the world out of its own powerful imagination, (in E. Agassiz, 1885, pp. 151– 152)