Lorenz Oken (1 August 1779 – 11 August 1851) was a German naturalist, botanist, biologist, and ornithologist. He became a professor of natural history at the University of Jena and from 1833 at the newly founded University of Zurich. He founded the journal Isis.
Oken was born Lorenz Okenfuss (German: Okenfuß) in Bohlsbach (now part of Offenburg), Ortenau, Baden, and studied natural history and medicine at the universities of Freiburg and Würzburg. He went on to the University of Göttingen, where he became a Privatdozent (unsalaried lecturer), and shortened his name to Oken. As Lorenz Oken, he published a small work entitled Grundriss der Naturphilosophie, der Theorie der Sinne, mit der darauf gegründeten Classification der Thiere (1802). This was the first of a series of works which established him as a leader of the movement of "Naturphilosophie" in Germany.
In it he extended to physical science the philosophical principles which Immanuel Kant (1724–1804) had applied to epistemology and morality. Oken had been preceded in this by Johann Gottlieb Fichte (1762–1814), who, acknowledging that Kant had discovered the materials for a universal science, declared that all that was needed was a systematic coordination of these materials. Fichte undertook this task in his "Doctrine of Science" (Wissenschaftslehre), whose aim was to construct all knowledge by a priori means. This attempt, which was merely sketched out by Fichte, was further elaborated by the philosopher Friedrich Schelling (1775–1854). Oken built on Schelling's work, producing a synthesis of what he held Schelling to have achieved.
Oken produced the seven-volume series Allgemeine Naturgeschichte für alle Stände, with engravings by Johann Susemihl (1767–1847), and published in Stuttgart by Hoffman between 1839 and 1841.
New system of animal classification
In the Grundriss der Naturphilosophie of 1802 Oken sketched the outlines of the scheme he afterwards devoted himself to perfecting. The position advanced in that work, to which he continued to adhere, is that "the animal classes are virtually nothing else than a representation of the sense-organs, and that they must be arranged in accordance with them." Consequently, Oken contended that there are only five animal classes based on the most developed organs in them:
Glossozoa, or fish, those animals in which a true tongue makes, for the first time, its appearance
Rhinozoa, or reptiles, in which the nose opens for the first time into the mouth and inhales air
Otozoa, or birds, in which the ear for the first time opens externally
Ophthalmozoa, or mammals, in which all the organs of sense are present and complete, the eyes being movable and covered with lids.
In 1805, Oken made a further advance in the application of the a priori principle in a book on generation (Die Zeugung), in which he maintained that "all organic beings originate from and consist of vesicles or cells. These vesicles, when singly detached and regarded in their original process of production, are the infusorial mass or protoplasma (Urschleim) whence all larger organisms fashion themselves or are evolved. Their production is therefore nothing else than a regular agglomeration of Infusoria—not, of course, of species already elaborated or perfect, but of mucous vesicles or points in general, which first form themselves by their union or combination into particular species."
A year after the production of this treatise, Oken developed his system one stage further, and in a volume published in 1806, written with the assistance of Dietrich von Kieser (1779–1862), entitled Beiträge zur vergleichenden Zoologie, Anatomie, und Physiologie, he demonstrated that the intestines originate from the umbilical vesicle, and that this corresponds to the vitellus or yolk-bag. Caspar Wolff (1735–1794) had previously claimed to demonstrate this fact in the chick (Theoria Generationis, 1774), but he did not see its application as evidence of a general law. Oken showed the importance of the discovery as an illustration of his system. In the same work Oken described and recalled attention to the corpora Wolffiana, or "primordial kidneys".
The reputation of the young Privatdozent of Göttingen had reached the ear of Johann von Goethe (1749–1832), and in 1807 Oken was invited to fill the office of Extraordinary Professor of the Medical Sciences at the University of Jena. He selected for the subject of his inaugural discourse his ideas on the "Signification of the Bones of the Skull", based on a discovery of the previous year. This lecture was delivered in the presence of Goethe, as privy councillor and rector of the university, and was published in the same year, with the title, Ueber die Bedeutung der Schädelknochen. With regard to the origin of the idea, Oken narrates in his Isis that, walking one autumn day in 1806 in the Harz forest, he stumbled on the blanched skull of a deer, picked up the partially dislocated bones, and contemplated them for a while, when it suddenly occurred to him, "It is a vertebral column!" At a meeting of the German naturalists held at Jena some years afterwards, Professor Kieser gave an account of Oken's discovery in the presence of the grand duke, which is printed in the Tageblatt, or "proceedings", of that meeting. The professor stated that Oken told him of his discovery when journeying in 1806 to the island of Wangerooge. On their return to Göttingen, Oken explained his ideas by reference to the skull of a turtle in Kieser's collection, which he disarticulated for that purpose. Kieser displayed the skull, its bones marked in Oken's handwriting.
Oken's lectures at Jena were wide-ranging, and were highly regarded at the time. The subjects included natural philosophy, general natural history, zoology, comparative anatomy, the physiology of man, of animals and of plants. The spirit with which he grappled with the vast scope of science is characteristically illustrated in his essay Ueber das Universum als Fortsetzung des Sinnensystems (1808). In this work he lays it down that "organism is none other than a combination of all the universe's activities within a single individual body." This doctrine led him to the conviction that "world and organism are one in kind, and do not stand merely in harmony with each other." In the same year he published his Erste Ideen zur Theorie des Lichts, &c., in which he advanced the proposition that "light could be nothing but a polar tension of the ether, evoked by a central body in antagonism with the planets, and heat was none other than a motion of this ether"—a sort of vague anticipation of the doctrine of the "correlation of physical forces".
In 1809 Oken extended his system to the mineral world, arranging the ores, not according to the metals, but according to their combinations with oxygen, acids and sulphur. In 1810 he summed up his views on organic and inorganic nature into one compendious system. In the first edition of the Lehrbuch der Naturphilosophie, which appeared in that and the following years, he sought to bring his different doctrines into mutual connection, and to "show that the mineral, vegetable and animal kingdoms are not to be arranged arbitrarily in accordance with single and isolated characters, but to be based upon the cardinal organs or anatomical systems, from which a firmly established number of classes would necessarily be evolved; that each class, moreover, takes its starting-point from below, and consequently that all of them pass parallel to each other"; and that, "as in chemistry, where the combinations follow a definite numerical law, so also in anatomy the organs, in physiology the functions, and in natural history the classes, families, and even genera of minerals, plants, and animals present a similar arithmetical ratio." The Lehrbuch procured for Oken the title of Hofrath, or court-councillor, and in 1812 he was appointed ordinary professor of the natural sciences.
In 1816, Oken began publication of his well-known periodical, Isis, eine encyclopädische Zeitschrift, vorzüglich für Naturgeschichte, vergleichende Anatomie und Physiologie. In this journal appeared essays and notices on the natural sciences and other subjects of interest; poetry, and even comments on the politics of other German states, were occasionally admitted. This led to representations and remonstrances from the governments criticized or impugned, and the court of Weimar called upon Oken either to suppress Isis or resign his professorship. He chose the latter alternative. The publication of Isis at Weimar was prohibited. Oken made arrangements for its issue at Rudolstadt, and this continued uninterruptedly until the year 1848.