Hoff, Karl Ernst Adolf von

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Hoff, Karl Ernst Adolf von

(b. Gotha, Germany, 1 November 1771; d. Gotha, 24 May 1837)

geology, geography.

Hoff was the son of Johann Christian von Hoff, privy councillor in Gotha, and Johanna Friederike Sophie von Avemann. After thorough private instruction at home, he attended the Gymnasium in Gotha from 1785 to 1788, when he enrolled in the University of Jena. Following his father’s wishes, he studied law and diplomacy as well as history at Jena, although he was drawn to mathematics and the natural sciences. In Jena and especially at the University of Göttingen, where he transferred after two years, he undertook additional studies in physics and the natural sciences. The latter were carried out mainly under the guidance of Blumenbach, who also introduced him to geology and with whom he was to remain close friends. In 1791 he entered Gotha’s civil service. He rose from Legationssekretär to director of the Ober-Consistorium (1829). As representative of the duchy of Gotha, he participated in diplomatic events of considerable import. He signed the Rhenish Confederation Act in 1806, took part in the Congress of Erfurt, and, in 1817 at Frankfurt am Main, signed for Gotha’s entry into the Germanic Confederation. He thus proved himself in his occupation at a time when Europe and the Thuringian duchies were extremely unstable and diplomacy a task of extraordinary difficulty. It is all the more to be wondered at that Hoff simultaneously accomplished first-rate work in a totally different field—scientific research, notably in geology and geography. Indeed, he introduced a new epoch of geological study which continues still.

Hoff’s development as a researcher was aided (as Reich has shown) by the lively intellectual life that prevailed in Gotha. Duke Ernst II encouraged scientific study, especially natural philosophy. Thus in 1786 he called the astronomer Zach to Gotha and built an observatory on the Seeberg, which came to be widely respected. The duke favored having at court civil servants who at the same time were scholars. Gotha’s publishing firms were extraordinary for a city of 10,000 inhabitants. For example, the Ettinger firm published 800 volumes of the city’s learned periodicals within twenty years. Hoff joined the circle that included his cousin Adolf Stieler and Ernst Friedrich von Schlotheim, a student of Werner who since 1793 had also been in the ducal service and who had become at the same time a leading paleontologist. Hoff devoted his free time to geology and mineralogy and utilized his official journeys to make field trips, visit major collections, and meet with experts. From Gotha he often made visits, with similarly interested friends, notably Wilhelm Jacobs, to the neighboring Thüringer Wald. There he visited mines, sometimes under the guidance of the mining director Voigt, a leading geologist and also a student of Werner; Voigt, however, had published the most solid demonstrations against the latter’s Neptunian theory. Since there existed no special periodical for geology and mineralogy, Hoff founded the Magazin für die gesamte Mineralogie, Geognosie und mineralogische Erdbeshreibung (1801). Despite the recognition it received, it ceased publication on the death of its publisher.

In 1801 Hoff began to publish his own works, which quickly widened his reputation and earned him the friendship of Humboldt, Buch, and Goethe. he wrote numerous articles on particular problems and the first detailed descriptions of the geology of individual regions, especially of Thuringia. of special significance was his Das teutsche Reich vor der französischen Revolution und nach dem Frieden zu Lunéville, of equal importance for both history and geography.

Hoff worked closely with the Gotha publishing firm of Perthes, which was at that time establishing its international reputation through the efforts of a few unselfish scholars (Hoff, for example, died poor). A map of Germany on which Stieler collaborated initiated Hoff’s many-sided and significant cartographical contributions. There also appeared a collaborative travel book, Der Thüringer Wald, in which Hoff treated the regional geology and mineralogy and Jacobs the botany and technology. Here, as in other of his writings, Hoff presented important data on stratigraphy and sediment formation, as well as on surface formation and the history of valleys. Moreover, he wrote an important article refuting the “aqueous” origin of basalt through the description of the basalt outcrops in the vicinity of Eisenach and of their contact effects. Here Hoff, originally a Neptunist himself, pointed out that the sandstone contiguous to the basalt was “altered in just such a way as would result from heating.”

All these accomplishments, which were based on careful studies and exact original observations, brought Hoff many honors and valued responsibilities. (In 1817 he shared in the reform of the University of Jena, in 1832 he was given the superintendence of all scientific and artistic collections in Gotha, and at the end of his life he was an honorary member of fifteen scientific societies.) Hoff’s studies have been superseded to the extent that his name would today be known to only a few specialists had not the findings of his detailed investigations led him to formulate a revolutionary, comprehensive principle and new method of study, Aktualismus (actualism).

At the beginning of the nineteenth century it was widely accepted that the alterations that the earth had experienced in the course of its history were produced by sudden events of catastrophic magnitude, which in force far surpassed existing phenomena. Diluvianism, or the attribution to the Flood of geological alterations, had been such a conception. Cuvier (1769–1832) developed the catastrophist theory in a particularly consistent manner. Upheavals of the earth’s crust had convulsed the sequence of rocks and destroyed the organic world, and several such catastrophes, with consequent new creations of life and intervening quiet periods, had taken place. Geological research was dependent on this theory. The forces currently acting on the earth, then, appeared too insignificant to produce fundamental changes in the structure of the earth’s surface.

At an early date Hoff presented observations which contradicted this view. For example, in 1807 he published an account of a newly formed island in the Havel River, and in 1812 he returned to Gottingen for a longer time in order to collect from the literature as many descriptions as possible of contemporary alterations in the surface of the earth. As early as 1814 he had formulated his new fundamental principle for the formation of Lower Permian sandstone conglomerates, namely, that less heed should be paid to great forces than to great periods of time. “With periods of time it is completely unnecessary to behave thriftily in the history of the earth, but one must surely do so with forces... this is certainly the case in geology: gutta cavat lapidem non vi, sed saepe cadendo (the drop hollows out the stone not by force, but by falling so often).”

The Sozietät der Wissensschaften in Göttingen had offered a prize for “the most thorough and comprehensive investigation of the alterations of the earth’s crust that can be demonstrated in its history, and for the application one can make of this knowledge through research on terrestrial upheavals that lie outside the realm of history.” Hoff’s prize-winning work, composed in 1821, appeared in 1822 as the first volume of his Geschichute der durch Öberlieferung nachgewiesenen natörlichen Veränderungen der Erdoberfläche. Opposing the given theme, which, as Vogelsang has emphasized, actually presupposed the catastrophist theory, Hoff insisted that one must in the first instance study the effect of those forces whose work we are able to observe today and apply this knowledge to the earliest history of the earth. Through these premises, later designated Aktualismus, he consciously rejected the catastrophist theory. He did not make headway at first. Not until Lyell’s Principles of Geology attained wide dissemination as a comprehensive textbook, supported by observations throughout the world, did actualism gain ascendancy and find lasting application in countless investigations.

Lyell, to be sure, went further than Hoff, in that he denied “any progress whatsoever in the developmental history of the earth, and speaks only of perpetual transformation, where others believe they find a very gradual development from a once totally different state” (B. Cotta, 1857). Lyell’s theory meant that in quantity and quality no forces and agencies other than those that we now experience have ever been active in the course of the history of the earth. Such a conclusion has more than once led to qualification or criticism of actualism in general (Andrée, Beurlen, Kaiser, et al.). This criticism met only Lyell’s uniformitarianism, however, not actualism in Hoff’s sense. Hoff himself had made allowance for this qualification in that he stated, “A limit will be found beyond which almost no known physical laws and facts will obtain... . But to search for these limits appears to us to be the most reasonable goal.” And Johannes Walther, the most important spokesman for actualism (he named it the “ontological method”), included in his work of 1893 a chapter on the limits of this method and declared “that there have existed in all geological periods biological and physical phenomena foreign to the present... . Only as we become fully conscious of the limit of the ontological method will it attain its true value.” From this vantage actualism has continued to justify itself. Hooykaas (1962) has also recently confirmed the distinction between Lyell’s and Hoff’s ideas.


I. Original Works. Reich (see below) lists seventy-seven works by Hoff. The most important are Das teutsche Reich vor der französischen Revolution und nach dem Frieden zu Luneville, 2 pts. (Gotha, 1801–1805); “Einige Bemerkungen über eine in der Havel entstandene Insel,” in Magazin naturforschenden Gesellschaft, 1 (1807), 233–240; Der Thiiringer Wald, 2pts (Gotha, 1807–1812); “Beobachtungen über die Verhaltnisse des Basaltes an einigen Bergen von Hessen und Thuringen,” in Magazin naturforschenden Gesellschaft, 5 (1810), 347–362; Gemalde der pyysischen Beschaffenheit, besonders der Gebirgsformationen Thuringens (Erfurt, 1812); Beschreibung des Thonschieferund Grauwackengebirges im Thuringer- und Frankenwalde,” in Leonhards Taschenbuch fur die gesammte Mineralogie, 7 (1813), 135–137; “Beschreibung des Trummergebirges und des alteren Flozgebirges, welche den Thuringer Wald umgeben,” ibid., 8 (1814), 319–438; “Merkwurdiges Vorkommen des Basaltes in der Gegend von Eisenach,”ibid., 15 (1821), 169–174; Statistische geographische Beschreibung der Lander des Herzoglichen Hauses Sachsen (Weimar, 1821); Geschichte der durch Uberlieferung nachgewiesenen naturlichen Veranderungen der Erdoberflache, 5 vols. (Gotha, 1822–1841); “Das Nadelohr im Tale der Werra und Einiges uber Talbildung,” in Leonhards Jahrbuch fur Mineralogie (1830), pp. 421–441; Hohenmessungen in und um Thuringen (Gotha, 1833); and Teutschland nach seiner naturlichen Beschaffenheit und seinen fruheren und jetzigen politischen Verhaltnissen (Gotha, 1838).

II. Secondary Literrature. On Hoff adolf and his scientific work, see K. AndrÈe, “Karl Ernst Adolf von Hoff also Schriftgelehrter und die Begrundung der modernen Geologie,” in Schriften der Küniglichen Deutschen Gesellschaftzu Königsberg, no. 4 (1930); Karl Beurlen, “Der Zeitbegriff in der modernen Naturwissenschaft und as Kausalitäsprinzip,” in Kant-Studien, 41 (1936), 16–37; “Die perodizität im erd- und lebensgeschichtlichen Entwicklungsgan,” in Abhndlungen und Verhandlungen de Naturwissenschaftlichen Vereins in Hamburg n.s. 12 (Hamburg, 1968), 5–25; Bernhard Cotta, “Einführung,” in the German trans. of Lyell’s Geology (Berlin, 1857); Bruno v. Feyberg, Die gelogische Erforshung Thüringens in ältere Zeit (Berlin, 1932); Helmut Höder. “Geologie als histroische Wissenschaft,” in Geol, Mitt., 3 (1962), 11–13; R. Hooykass, The Principle of Uniformity in Geology, Biology and Theology, 2nd ed. (Leiden, 1962); Erich Kaiser, “Der Grundsatz des Aktualismus in der Geologie,” in Zeitschrift der Deutschen geologischen Gesellschaft, 83 (1931), 389–407; Otto Reich Karl Ernst Adolf von Hoff, der Bahnbrecher moderner Geologie (Leipzig, 1905), the most complete biography available; H. Vogelsang, Philosphie der Geologies (Bonn, 1867); JOhannes Walther Einleitung in die Geologies als historische Wissenschaft, 3 vols. (Jena, 1893–1894); and Karl Alfred von Zittel, Geschichte der Geologie und Paläontologies (Munich-Leipzig, 1899)

B. v. Freyberg