New wine in old bottles: the historiography of a paradigm change

Geomorphology, 5 (1992) 251-263

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Elsevier Science Publishers B.V., Amsterdam

New wine in old bottles: the historiography of a paradigm change Dorothy Sack Department of Geography, University of Wisconsin, Madison, W15 3 706, USA (Received November 1l, 1991; revised and accepted April 9, 1992 )

ABSTRACT Sack, D., 1992. New wine in old bottles: the historiography of a paradigm change. In: J.D. Phillips and W.H. Renwick (Editors), Geomorphic Systems. Geomorphology, 5:251-263. This paper historiographically analyzes the enunciation of the American, systematic-process geomorphology paradigm in the mid-20th century, with particular focus on notions concerning Gilbert and systems. Selected contributionsby Strahlet, Hack, and Chorley are emphasized because of their influential roles in pronouncing and elaborating process geomorphology. Articulation of the emerging paradigm contributed to the installation of Gilbert as its figurehead and established systems analysis as a fundamental tool. Gilbert was an appropriate figurehead for the new paradigm because he had worked outside of the Davisian paradigm during the Davisian era, had done process geomorphology, had applied the method of systems analysis, and was very well respected. Identifying Gilbert as the archetypal process geomorphologist helped sanction the process paradigm, d!stance it from Davisian geomorphology, and ease the paradigm change. Strahler's portrayal of Gilbert, however, incorrectly implies that Gilbert had actively advocated process geomorphology in a competition with Davis and the Davisian geographical cycle. Gilbert, Strahler, and Hack each applied the thermodynamicallybased method of systems analysis to process geomorphology, but Chorley advocated von Bertalanffy's philosophically based general system theory instead. Gilbert, Strahler, and Hack did not apply general system theory to geomorphology, as Chorley suggested they had. Recognizing these and other notions as revisionist aids in recovering a truer understanding of the actual contributions of people important in the history of geomorphology.

Introduction

G.K. Gilbert (Fig. 1 ) is considered the "intellectual patron saint" of modern American geomorphology (Tinkler, 1985, p. 198 ), which emphasizes the approach of systems analysis and the theme of process geomorphology. The current geomorphic paradigm replaced the historical-evolutionary paradigm of W.M. Davis during a transition period in the middle of the 20th century. The paradigm change generated an important body of primary literature (e.g., Strahler, 1950a, b, 1952; Hack, 1960; Chorley, 1962) which has since been the subCorrespondence to: D. Sack, Department of Geography, University of Wisconsin, Madison, WI 53706, USA.

ject of elaboration, interpretation, and commentary (e.g., Judson, 1960; Schumm and Lichty, 1965; Smalley and Vita-Finzi, 1969; Flemal, 1971; Higgins, 1975; Tinkler, 1985; Ritter, 1988). In the enthusiasm to advocate or elaborate a new paradigm, revisionist notions about the history of the field or individuals who worked within it tend to creep into the literature (Herries Davies, 1989). The purpose of this paper is to historiographically analyze early literature enunciating the systematic-process paradigm in geomorphology, with particular emphasis on notions concerning Gilbert and systems. In this discussion, the terms systematic-process geomorphology and process geomorphology are used as general synonyms for both quantitative-dynamic geo-

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Report on the Geology of the Henry Mountains (1877), Lake Bonneville (1890), and Hydraulic-Mining Debris in the Sierra Nevada ( 1917 ). When studying a given landform type, such as a laccolith, a fault-block mountain, a beach, or a stream, Gilbert's approach was to identify and analyze the relevant external and internal forces. He tended to analyze landforms, at least conceptually, using the free-body diagram approach of engineering mechanics. He treated landforms as though they were the resulting summation of applied forces acting on resisting earth materials. In his explanation of the laccolith, Gilbert ( 1877 ) stated:

Fig. 1. G.K. Gilbert. Photograph taken in 1898. U.S. Geological Survey Photographic Library Portrait 111.

morphology (Strahler, 1950a) and the dynamic equilibrium theory (Hack, 1960). Because of the historiographic nature of this analysis primary sources are emphasized.

Gilbert's geomorphic approach and scientific method Gilbert worked as a government geologist from 1869 until his death in 1918, but he also considered himself a geographer (Gilbert, 1909a ). Although Gilbert never held a permanent university faculty position, he was nevertheless an educator, too (Sack, 1991 ). Gilbert taught courses at two universities, lectured at many others, wrote a major pedagogical paper (1886), coauthored physical geography textbooks with A.P. Brigham ( 1902, 1903), and educated numerous earth scientists through personal exchange, oral papers, and published works. His approach to geomorphology is best discerned directly from his numerous publications; especially revealing in this regard are his

When a lava forced upward through the strata reaches the level at which under the law of hydrostatic equilibrium it must stop. we may conceive that it expands along some plane of bedding in a thin sheet, until its horizontal extent becomes so great that it overcomes the resistance offered by the rigidity of its cover, and it begins to uplift. The direction of least resistance is now upward, and the reservoir of lava increases in depth instead of width. The area o f a laccolite thus tends to remain at its minimum limit, and may be regarded as more or less perfectly an index of that limit (pp. 82-83) .... The laccolite in its formation is constantly solving a problem of'least force', and its form is the result (p. 85).

Gilbert (1886, 1896) provided explicit statements regarding his conception of the scientific method. To Gilbert (1886, p. 285), "scientific research consists of the observation of phenomena and the discovery of their relations." The scientist endeavors to record observations as objectively as possible, not indiscriminantly, but by selecting phenomena believed to be relevant to the problem at hand (Gilbert, 1886). Each observation has more than one antecedent and more than one consequent: Antecedent and consequent relations are therefore not merely linear, but constitute a plexus; and this plexus pervades nature .... It is the province of research to discover the antecedents of phenomena (Gilbert, 1886, p. 286).

The investigator attempts to find an explanation, the antecedents, of the observed phenomena by testing hypotheses, and it is most effi-

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cient to test many hypotheses at once. Hypotheses of explanation are derived by analogy from explanations of other phenomena of which the researcher is aware. In his methodological papers, Gilbert ( 1886, 1896) used actual field problems to illustrate the utility of this scientific method of multiple working hypotheses derived by analogy. In addition, he employed this method in his research papers (e.g., Gilbert, 1877, 1890, 1904). For example, in the Report on the Geology of the Henry Mountains, Gilbert ( 1877, p. 84 ) stated outright that: I am led by the analogy of allied problems in mechanics to assume that the resistance of the body of strata varies with some power of its depth...

The Davisian era of American geomorphology

W.M. Davis (Fig. 2), who lived from 1850 to 1934, is well known for his influential the-

Fig. 2. W.M. Davis (from Buwalda, 1934, p. 384). Reprinted with permission o f the American Association for the Advancement of Science, © AAAS.

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ory of landscape development, the geographical cycle. Davis's ( 1889, 1899 ) theory is based on an organic analogy drawn from the Darwinian theory of evolution (Stoddart, 1966). Davis theorized that geomorphic landscapes are the manifestation of structure, process, and stage, or time. Given certain assumptions regarding structure and process, Davis believed that landscapes evolve through the successive stages of youth, maturity, and old age in a deterministic sequence. To Davis, identification of a landscape's current stage, then, provides information on its past and future configuration. Davis's theory was widely accepted for at least three reasons. First, application of the lifecycle analogy from biology to other fields was very fashionable at the time (Chorley et al., 1973; Higgins, 1975; Ritter, 1978). In addition, the nonquantitative nature of the geographical cycle made it understandable to a large sector of the population. Finally, as a Harvard University professor with considerable pedagogic skill, Davis taught his model to numerous students, many of whom subsequently taught it to their students (Flemal, 1971; Chorley et al., 1973; James and Martin, 1981). Davis's theory of landscape development was the dominant paradigm for American geomorphic study from the late 19th to the mid20th century; however, a review of Gilbert's publications reveals that none of his geomorphic investigations were conducted on or within that theory. On the other hand, such a review does show that Gilbert occasionally used Davisian terminology (e.g., Gilbert, 1890, p. 63, 1893, p. 262, 1909b, p. 344) and that he defended its use to others (Gilbert, 1905; Higgins, 1975 ). During the Davisian era, Gilbert continued to employ his mechanical-process approach to geomorphology and the scientific method of multiple working hypotheses. In doing so he contributed to such topics as glacial geomorphology ( 1903, 1906a,b), earthquakes and faulting ( 1907, 1909a, 1928), flu-

254 vial geomorphology ( 1914, 1917 ), and mountain building ( 1928 ). Gilbert was highly regarded by his contemporaries in spite of the fact that he did not embrace the dominant geomorphic paradigm of the era (Chamberlin, 1918; Davis, 1918, 1927; Fairchild, 1918; Merriam, 1919; Andrews, 1920; Mendenhall, 1920). Gilbert was not the only American investigator who worked outside of the dominant geomorphic paradigm during the Davisian era (Strahler, 1950a, b, 1952; Young, 1972; Tinkler, 1985). Other early process studies were conducted, for example, by Andersson ( 1906 ), Fenneman (1908), and Lawson ( 1915) on slopes; by Leighly ( 1932, 1934), Rubey ( 1933, 1938), Hjulstrom (1935), Matthes (1941, 1949 ), and Horton ( 1945 ) on streams; and by Bagnold ( 1941 ) on eolian dunes. Although the Davisian theory was widely accepted by American geomorphologists in the first half of the 20th century, it was criticized openly by some contemporaries. Tarr ( 1898 ), Shaler (1899), Smith (1899), and Marks ( 1913 ) published early papers questioning its terminology and global utility (Hack, 1975; Higgins, 1975; Bishop, 1980; Tinkler, 1985). Later in the Davisian era, Crickmay ( 1933, p. 338 ) outlined his objections to "the course the cycle is supposed to follow in its late stages." Fenneman (1936, 1939) and Bryan (1941) acknowledged the existence of contemporary criticisms of Davisian geomorphology. Horton (1945) noted confusion caused by misapplication of the Davisian stage terms, and maintained that his hydrophysical work on streams and drainage basins was merely quantifying the qualitative observations of Playfair and Davis. Bryan (1950) argued that the Davisian normal climate is actually the exceptional case. Theoretical alternatives to the Davisian geographical cycle were presented during the Davisian era by Penck (1924) and later by King ( 1953 ), but neither received a large American following (Judson, 1960; Flemal, 1971; Higgins, 1975; Tinkler, 1985).

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The paradigm change Dating the paradigm change

The paradigm change from historical-evolutionary to process geomorphology occurred over a transitional period within the middle of the 20th century, and cannot be strictly assigned to any single year (Ritter, 1988). Nor did disenchantment with Davisian geomorphology necessarily increase at the same rate as interest in process studies. Hence some commentators suggested that initially a paradigmatic vacuum was left upon renunciation of the geographical cycle (Hack, 1960, 1975; Judson, 1960; Ritter, 1978 ). Tinkler ( 1985, p. 153), however, affirmed that the rise of process studies was instrumental in turning the tide against Davisian geomorphology. Process studies and criticism of the geographical cycle appeared throughout the Davisian era, but both started to accelerate in the 1930s (Hack, 1960; Chorley, 1965; Flemal, 1971; Tinkler, 1985). World War II interrupted the momentum of this pre-War trend (Tinkler, 1985), but may also have caused an increased interest in process studies (Ritter, 1988 ). Significant impact of process geomorphology in American universities occurred when student populations grew in the 1960s (Tinkler, 1985). Although criticism of Davisian geomorphology culminated in the early 1960s (Tinkler, 1985), sources from the first half of the 1970s refer to holdouts to Davisian geomorphology in the teaching profession and among conservative scholars. Step 1 - Strahler's pronouncement

Despite the transitional nature of the paradigm change, the early 1950s mark a watershed in published attitudes toward the Davisian theory of geomorphology. The collection of papers written for a 1950 Association of American Geographers geomorphology symposium held in honor of the 100th anniversary

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of Davis's birth contains a revealing assortment of viewpoints. Martin (1950) provided the requisite laudatory essay on Davis, whereas Cotton (1950) and Peltier (1950) elaborated, within the Davisian scheme, details of the tectonic and periglacial landscapes, respectively. Bryan (1950) was generally critical of Davisian geomorphology and attempted to prescriptively distinguish geological geomorphology from geographical geomorphology. Although Baulig (1950) was supportive of the geographical cycle theory his defensive couching of it in process terminology elevated process studies to the role of validator. Finally, A.N. Strahler ( 1950a, p. 209) (Fig. 3) took the opportunity of the symposium in honor of Davis to assail Davisian geomorphology as a superficial cultural pursuit of geographers that is completely inadequate as a natural science. Strahler (1950a) maintained that those geomorphologists wishing to make substantial contributions to science must adopt what he termed the quantitative-dynamic approach to landform studies. Strahler's clarion call to the quantitative-dynamic approach was articulated through three papers (Strahler, 1950a,b, 1952). In these, he was quick to indicate that this geomorphic tradition had a history and to identify people, including Gilbert, who had successfully used this

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approach in the past. Strahler's primary contribution, then, was not that he devised the approach, for he did not, but that he presented it clearly and argued so convincingly for its adoption. As outlined by Strahler (1950a, 1952), the goal of this approach is to quantitatively determine the relationships between process and form. To accomplish this goal, geomorphic phenomena must be studied as: various kinds of responses to gravitation and molecular shear stresses acting upon materials behaving characteristically as elastic or plastic solids, or viscous fluids (Strahler, 1952, p. 937).

Strahler ( 1950a, 1952) described this work as demanding because it requires considerable expertise in physical science, including such subjects as geology, mechanics, thermodynamics, hydrology, mathematics, and statistics. In sharp contrast to the Davisian emphasis on stage of landscape evolution, the quantitative-dynamic approach focusses on the processes (applied force and internal resistance) resulting in specific landforms. In delineating the quantitative-dynamic approach, Strahler ( 1950a,b, 1952 ) applied terms used in thermodynamic systems analysis. At first he employed the terms casually, i.e., without reference, stating that "the concept of a steady state in an open system seems a logical replacement for the idea of 'maturity' ... (Strahler, 1950a, pp. 212-213)." Next, in his application of the quantitative-dynamic approach to a field investigation, Strahler (1950b) extended the use of systems terminology and discussed the definition of terms. He suggested that: a graded drainage system is perhaps best described as an open system in a steady state (von Bertalanffy, 1 9 5 0 [ b ] ) which differs from a closed system in equilibrium in that the open system has import and export of components (Strahler, 1950b, p. 676).

Fig. 3. A.N. Strahler, ca. 1952.

In his most complete statement of the process approach to geomorphology Strahler (1952,

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pp. 934-935 ) went farther, declaring that: geomorphology will achieve its fullest development only when the forms and processes are related in terms of dynamic systems and the transformations of mass and energy considered as functions of time (von Bertalanffy, 1950a, b).

Strahler (1952, p. 935) used systems terminology in a way appropriate to the established approach, i.e., methodology, of thermodynamic systems analysis (Smalley and VitaFinzi, 1969), and did not discuss von Bertalanffy's (1950a,b) philosophically based general system theory (Harvey, 1969 ) despite the fact that he provided references to that contemporary work. Nevertheless, Strahler's (1950a, 1952) references to von Bertalanffy's (1950a,b) papers introduced the concept of general system theory, as von Bertalanffy called it, into process geomorphology (Chisholm, 1967; Smalley and Vita-Finzi, 1969 ). General system theory had recently been postulated by yon Bertalanffy (1950a,b) as a unifying theory of science, "a new scientific doctrine of 'wholeness' " ( v o n Bertalanffy, 1950a, p. 142 ) with the aim of establishing the principles valid for systems in general, applicable to all scientific disciplines. Although Strahler (1950a, 1952) emphasized the fact that most of the recent quantitative-dynamic geomorphic studies had been conducted by engineers, he did recognize it as the approach that Gilbert had used. However, Strahler (1950a) also described that method as having been "endorsed" (p. 209 ) and "promoted strongly" (p. 210) by Gilbert. Further, Strahler (1950a, p. 210) stated that: had Gilbert's philosophy of physical geology prevailed among students of landforms the analysis of slopes would not have been so long delayed. As it was, apparently Davis won over a large following and the study of landforms became dominated by [Davisian geomorphologists].

Taken together, these statements lead readers to incorrectly infer that Gilbert actively sought adherents to a quantitative-dynamic school of thought and that Gilbert and Davis were com-

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peting for ascendency of their rival geomorphic approaches. Certainly by using it, Gilbert endorsed, i.e., approved of, the quantitative-dynamic approach; he did not, however, promote it in the sense of expressly trying to convince others to use it. Even in his methodological papers Gilbert ( 1886, 1896 ) did not proselytize, but instead merely presented his conception of the method of multiple working hypotheses and the origin of hypotheses by analogy. Davis ( 1927, p. 1 ) described Gilbert with these words: It was from no urgency or insistence on his part that his opinions were adopted, but from the persuasively convincing logic with which they were set forth .... Not he, but the facts that he marshaled, clamored for the acceptance of the explanation that he had found for them.

Strahler ( 1952 ) recognized that in reality the quantitative-dynamic approach to geomorphology could not be completely divorced from the historical approach. However, by portraying Gilbert and Davis as competitors who embraced the timeless dynamic and timebound historical approaches to geomorphology, respectively, Strahler (1950a, 1952) took the first step in establishing what was to become an almost complete, and in some important respects fallacious, antithetical characterization of Gilbert and Davis (Sack, 1991 ). Step 2 - H a c k ' s elaboration

In 1960, J.T. Hack (Fig. 4) published an elaboration of the process paradigm that Strahler ( 1950a,b, 1952 ) had initially framed. Hack expanded the systematic, quantitativedynamic approach of Strahler into the dynamic equilibrium theory, which he viewed as applicable to general geology as well as to the study of topographic form and process. Hack (1960) outlined his dissatisfaction with the Davisian theory of landscape evolution, and contended that explanations of present landforms could instead be found in present processes through the study of the spatial relations

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In contrast with Strahler, Hack did not reference von Bertalanffy's (1950a,b) general system theory. Hack's elaboration of Strahler's paradigmatic statement, therefore, reinforced the association of both systems analysis and the name of Gilbert with the process geomorphology paradigm. The triumvirate of process, systems analysis, and Gilbert makes logical sense. Gilbert surely practiced process geomorphology. Moreover, his descriptions of the plexus of antecedent and consequent relations (Gilbert, 1886, p. 286; quoted above) and the interdependence of drainage system tributaries (Gilbert, 1877, p. 118 ) appears to be conceptually equivalent to systems analysis:

Fig. 4. J.T. Hack. Photograph taken in 1970. U.S. Geological Survey Photographic Library Portrait 1198.

between geomorphic phenomena. Following Strahler, Hack credited Gilbert with early use of the process approach to geomorphology,thus reinforcing the association between Gilbert and the emerging paradigm. Even the term chosen by Hack to describe his theory, dynamic equilibrium, had been employed by Gilbert ( 1877, p. 117) 83 years earlier in the Report on the Geology of the Henry Mountains to describe "the tendency to equality of action." As Strahler had done with the quantitative-dynamic approach to geomorphology, Hack applied to his theory terms and concepts by analogy from the thermodynamic method of systems analysis, thus further associating process geomorphology with systems analysis. For example, he stated: The landscape and the processes molding it are considered a part of an open system in a steady state of balance in which every slope and every form is adjusted to every other. Changes in topographic form take place as equilibrium changes... (Hack, 1960, p. 81 ).

For in each basin all lines of drainage unite in a main line, and a disturbance upon any line is communicated through it to the main line and thence to every tributary. And as any member of the system may influence all the others, so each member is influenced by every other. There is an interdependence throughout the system.

Because Gilbert (1877, 1890) cited works by one of the founders of the science of thermodynamics, W.J.M. Rankine, it is likely that he purposefully applied analytical techniques from that field to geomorphology by analogy (Baker and Pyne, 1978 ). It is appropriate to consider at this point the utility of having the emerging paradigm of systematic-process geomorphology become increasingly associated with Gilbert. Obviously thorough presentation of a suggested research model requires a literature review; by mentioning Gilbert's use of process geomorphology, Strahler and Hack were being conscientious scholars giving credit to a pioneer in the field. Tinkler (1985, pp. 229-230), however, notes an apparent tendency for followers of a newly accepted paradigm to seek "a more respectable ancestry" than that available from the period dominated by the discarded paradigm. In this case, it was logical for Gilbert to become the ancestor because he had worked outside of the Davisian paradigm, had in fact

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practiced process geomorphology, and was very well respected. Finally, because American geomorphology had been dominated by a single, strong personality, Davis, for over 50 years, it may have been psychologically easier for prospective adherents to embrace the new paradigm once they had a figurehead to go with it. Acquiring a figurehead, and one as impeccable as Gilbert, helped sanction the emerging paradigm, distance it from the rejected one, and ease the paradigm change. Step 3 - Chorley's embellishment

In 1962 R.J. Chorley (Fig. 5) published a U.S. Geological Survey paper on the notion of systems in geomorphology. In it, Chorley (1962) expanded upon the concepts that Strahler (1950a, b, 1952) and Hack (1960) had introduced to the field. Chorley provided examples illustrating the meaning of systems terms and the relevance of systems concepts to

Fig. 5. R.J. Chorley. Photograph taken in 1962.

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geomorphology. Chorley (1962, p. B2), however, went beyond application of the method of systems analysis and advocated a "framework of investigation based on general systems theory," which Strahler (1950a, b, 1952) and Hack (1960) had not done. Because yon Bertalanffy's (1950a,b) philosophy of general system theory holds that science can be unified through the use of systems concepts, methodological use of systems analysis logically follows philosophical acceptance of the theory (Harvey, 1969). "It is important to recognise, however, that the adoption of a methodological position does not entail the adoption of a corresponding philosophical position" (Harvey, 1969, p. 7 ). One does not have to embrace general system theory to use the systems approach. Because most of Chorley's ( 1962 ) discussion relates to the methodological application of systems analysis to geomorphology, the paper is generally relevant to readers who accept systems analysis as only an approach as well as to those who embrace the philosophical framework of general system theory. In the 1962 paper, Chorley contrasted Davisian historical-evolutionary geomorphology, which he described as containing elements of closed-system thinking, with process-oriented geomorphology, which he associated with Gilbert and open-system analysis. Thus Chorley (1962) elaborated the use of the systems approach to geomorphology, perpetuated Gilbert as the figurehead for the process geomorphology paradigm, extended the antithetical characterization of Gilbert and Davis, and further distanced the process paradigm from the Davisian paradigm. Although Chorley (1962, p. B6) admitted that most geomorphic phenomena could be studied from both the historical closed-system and the process open-system perspectives, he advocated the open-system framework of general system theory. In his view, some of the advantages of the open-system approach include ( 1 ) focus on the adjustment between form and process, (2) emphasis on the multivariate character of many geo-

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morphic problems, (3) utility in regions where the erosional history is blurred, and (4) its potential contribution to human geography, which has traditionally been influenced by geomorphology (Chorley, 1962 ). Whereas Chorley ( 1962 ) listed specific criticisms of the closed-system approach and specific benefits of the open-system approach to geomorphology, his arguments for embracing general system theory are less tangible. Chorley ( 1962, p. B2 ) apparently addressed this issue in summarizing "the advantages of operating within an appropriate general systematic framework." According to Chorley ( 1962, p. B2 ) such a course of action: may increase the scope of the study, make possible correlations and associations which would otherwise be impossible, generally liberalize the whole approach to the subject and, in addition, allow an integration into a wider general conceptual framework.

Both Chisholm (1967) and Smalley and Vita-Finzi ( 1969 ) criticized Chorley's ( 1962 ) paper. Chisholm ( 1967 ) disagreed with Chorley's ( 1962 ) classification of the Davisian approach as being largely closed-system thinking. He argued that all geomorphic systems are open, and that all approaches to their study, even the Davisian approach, are open-system analyses (Chisholm, 1967 ). Chisholm ( 1967 ) and Smalley and Vita-Finzi (1969) emphasized the distinction between the well-established and useful method of systems analysis, which has its roots in thermodynamics, and general system theory, which had been proclaimed as being a unifying theory of science (von Bertalanffy, 1950a,b). Chisholm (1967, p. 51 ) was "baffled to know what is added by general systems theory." Both critiques concluded that in its incorporation into geomorphology, "general systems theory seems to be an irrelevant distraction" (Chisholm, 1967, p. 51; Smalley and Vita-Finzi, 1969). An additional criticism of Chorley's embellishment of the process paradigm with general system theory stems from an historical analy-

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sis of the paradigm-change literature. This analysis reveals that Chorley ( 1962, p. B 1 ) revised the early history of the paradigm change by describing Strahler ( 1950b, 1952 ) and Hack (1960) as having applied general system theory to geomorphology. Moreover, by depicting Gilbertian geomorphology as representing the more advantageous open-system framework of general system theory, Chorley (1962) also leads readers to associate Gilbert with the philosophy. Strahler, Hack, and Gilbert certainly applied methodological concepts from thermodynamic systems analysis to geomorphology, but none of them discussed the philosophically based general system theory in either name or spirit. Of the three, only Strahler (1950a, 1952) happened to include von Bertalanffy as a reference for the definitions of open and closed systems (Smalley and VitaFinzi, 1969). Chorley's (1962) attempt to associate general system theory with the emerging geomorphic paradigm, its early proponents (Strahler and Hack), and its personification (Gilbert) may have been driven by a conscious or unconscious desire to make the new paradigm seem modem and at the cutting edge of contemporary theoretical science. Davisian geomorphology had become outmoded; it had not kept in scientific pace with other natural sciences. Strahler ( 1950a, b, 1952) had made this fact painfully public. By looking to Gilbert for its personification, the early advocates of the quantitative-dynamic paradigm were providing their paradigm with a highly respected personage, but one from the past. Thus the emerging paradigm could also be accused of being outmoded. Having a figurehead from the past could be offset by embracing a contemporary theory of science. Moreover, describing Gilbert as having worked within the open-system framework of general system theory made the figurehead appear modem, even though it was placing new wine in old bottles. By associating the new geomorphic paradigm and its figurehead with a recent scientific

260 theory, Chorley ( 1962 ) may also have been attempting to fortify geography in general. Chorley ( 1962, p. B9) had expressed an interest in the health of geography; as noted above, he contended that one advantage of the open-system approach to geomorphology was its potential role in strengthening human geography, which had traditionally been influenced by developments in geomorphology. At approximately this time, American human geographers were responding to their own Strahlerian call to abandon the outmoded, largely prescientific regional paradigm and adopt a quantitative-dynamic approach (Schaefer, 1953; Johnston, 1987 ). According to Chorley ( 1962, p. B9), open-system thinking would improve human geography by making it less deterministic. The open-system approach might also help unify the seemingly disparate human and physical geographic subfields. Moreover, if human geographers were to follow geomorphologists in adopting general system theory, geography in general might benefit in reputation by being associated with a recent scientific theory. Summary and conclusions Many geomorphologists, including critics of the geographical cycle and investigators who conducted process studies, contributed to the mid-20th century geomorphic paradigm change. Papers by Strahler, Hack, and Chorley are emphasized in this analysis because of their influential roles in pronouncing and elaborating the process geomorphology paradigm, and thus in effecting the paradigm change. Strahler, Hack, and Chorley each associated Gilbert and systems analysis with process geomorphology. In their discussions of these topics, Strahler (1950a) and Chorley ( 1962 ) revised, by implication or declaration, selected aspects of the history of American geomorphology, and thereby fostered the paradigm change. In delineating, espousing, and applying process geomorphology, Strahler ( 1950a, b, 1952 )

D.SAC~ employed terminology from the thermodynamically based method of systems analysis, referenced but did not discuss von Bertalanffy's philosophically based general system theory, and recognized that process geomorphology is essentially the approach to the subject that Gilbert (e.g., 1877, 1890) had used. In addition, Strahler's (1950a) work leads readers to infer that Gilbert had actively sought adherents to process geomorphology and that Gilbert and Davis had competed for ascendency of their respective approaches. The implication that Gilbert and Davis were rivals began what would later in the 20th century become an exaggerated dichotomous characterization that at least partially misrepresents Gilbert. Davis, for example, is known as a geographer and educator of substantial pedagogic skill whose work emphasized the latest chapter in earth history (e.g., Chorley and Beckinsale, 1980; Pyne, 1980). In contrast, Gilbert is described as having been exclusively a geologist and an investigator, who was unsuited to teaching, and who never used stratigraphy, which is a principal tool of the earth historian (e.g., Pyne, 1979, 1980). Certainly the two men were very different in many respects, and some of the several opposing characterizations that have been made are appropriate. However, Gilbert's significant geographical ties, his role as educator, his stratigraphic work, and his important contributions to earth history have been overlooked in order to strengthen the dichotomy (Sack, 1991). Whereas Strahler separately associated process geomorphology with both systems analysis and with Gilbert, Hack (1960) completed the ternary relationship by indicating the link between Gilbert and systems analysis. Without any mention of general system theory or von Bertalanffy, Hack (1960) showed how Gilbert's (1877) concept of dynamic equilibrium was an integral part of the systems analysis method. Hack (1960), therefore, strengthened and perpetuated the trinity of

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process geomorphology, systems analysis, and Gilbert. Chorley (1962) heightened the contrast between Davisian geomorphology and Gilbertian geomorphology, and therefore also the antithetical characterization of Davis and Gilbert, by describing the two approaches as largely closed-system and open-system thinking, respectively. He went beyond the application of systems analysis to suggest that geomorphologists adopt for a theoretical framework von Bertalanffy's (1950a, b) general system theory, which is essentially a philosophy (Harvey, 1969). Chorley ( 1962, pp. B l-B2) revisionistically described Strahler and Hack as having applied general system theory to geomorphology, and at least linked Gilbert with the philosophy by equating Gilbertian geomorphology with the open-system framework of general system theory. In reality, Gilbert, Strahler, and Hack had simply applied the method of systems analysis to geomorphology by analogy from thermodynamics. The establishment of Gilbert as the figurehead for process geomorphology accomplished useful things for the emerging paradigm. First, it helped sanction the new approach by associating it with a very well-respected geomorphologist. Second, because the historical-evolutionary paradigm had been dominated by a single, strong personality for decades, acceptance of the process paradigm by prospective adherents may have been psychologically eased once it had its own powerful figurehead. Finally, depicting Gilbert and Davis in opposing terms helped to distance the new paradigm from the old one. Chorley's (1962) attempt to link general system theory with Strahler, Hack, Gilbert, and the process paradigm may have been motivated by a conscious or unconscious desire to portray the paradigm as being at the cutting edge of theoretical science. This would offset the backward-looking impression given by having a geomorphologist of the past as the paradigm's archetype. Moreover, if geomor-

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phology were to embrace general system theory, geography as a whole might follow. Chorl e y ( 1962, p. B9) contended that the opensystem framework of general system theory would be helpful in human geography. In the mid-20th century, geography's reputation could have been enhanced by the association with a contemporary theory of science. Revisionist notions revealed in this paper spawned an almost complete antithetical characterization of Gilbert and Davis (e.g., Baker and Pyne, 1978; Pyne, 1980; Ritter, 1988)and were probably largely responsible for much subsequent confusing of systems analysis (the methodology ) with general system theory (the philosophy) (e.g., King, 1966; Higgins, 1975; Baker and Pyne, 1978). Whether intentional or not, it is important that historical misconceptions, such as the notions that Gilbert competed with Davis by advocating process geomorphology and that Gilbert applied general system theory to geomorphology, be exposed. By making and perpetuating these errors, geomorphologists whiggishly reinterpret the history of American geomorphology and the contributions of at least one of its greatest investigators. In this case, such revisionist history contorts Gilbert from what he really was into what later practitioners consciously or unconsciously wanted him to be.

Acknowledgments I am grateful to three anonymous reviewers for their helpful suggestions, and to R.J. Chorley and A.N. Strahler for kindly providing photographs.

References Andersson, J.G., 1906. Solifluction, a component of subaerial denudation. J. Geol., 14:91-112. Andrews, E.C., 1920. Grove Karl Gilbert. Sierra Club Bull., 11: 60-69. Bagnold, R.A., 1941. The Physics of Blown Sand and Desert Dunes. Methuen, London, 265 pp. Baker, V.R. and Pyne, S.J., 1978. G.K. Gilbert and mod-

262 ern geomorphology. Am. J. Sci., 278: 97-123. Baulig, H., 1950. William Morris Davis: master of method. Ann. Assoc, Am. Geogr., 40:188-195. Bishop, P., 1980. Popper's principle of falsifiability and the irrefutability of the Davisian cycle. Prof. Geogr., 32: 310-315. Bryan, K., 1941. Physiography. In: Geology, 1888-1938, Fiftieth Anniversary Volume. Geol. Soc. Am., New York, pp. 1-15. Bryan, K., 1950. The place of geomorphology in the geographic sciences. Ann. Assoc. Am. Geogr., 40:196-208. Buwalda, J.P., 1934. The progress of science: William Morris Davis, an appreciation. Sci. Mon., 38: 384-387. Chamberlin, T,C., 1918. Grove Karl Gilbert. J. Geol., 26: 375-376. Chisholm, M., 1967. General systems theory and geography. Trans. Inst. Br. Geogr., 42: 45-52. Chorley, R.J., 1962. Geomorphology and general systems theory. U.S. Geol. Surv. Prof. Pap., 500-B: B1-B10. Chorley, R.J., 1965. A re-evaluation of the geomorphic system of W.M. Davis. In: R.J. Chorley and P. Haggett (Editors), Frontiers in Geographical Teaching. Methuen, London, pp. 21-38. Chorley, R.J. and Beckinsale, R.P., 1980. G.K. Gilbert's geomorphology. In: E.L. Yochelson (Editor), The Scientific Ideas of G.K. Gilbert. Geol. Soc. Am. Spec. Pap., 183: 129-142. Chorley, R.J., Beckinsale, R.P. and Dunn, A.J., 1973. The Life and Work of William Morris Davis. Methuen, London, 874 pp. Cotton, C.A., 1950. Tectonic relief. Ann. Assoc. Am. Geogr., 40: 181-187. Crickmay, C.H., 1933. The later stages of the cycle of erosion. Geol. Mag., 70: 337-347. Davis, W.M., 1889. The rivers and valleys of Pennsylvania. Nat. Geogr. Mag., 1: 183-253. Davis, W.M., 1899. The geographical cycle. Geogr. J., 14: 481-504. Davis, W.M., 1918. Grove Karl Gilbert. Am. J. Sci., 46: 669-681. Davis, W.M., 1927. Biographical memoir Grove Karl Gilbert, 1843-1918. Mere. Nat. Acad. Sci., 21(5): 1303. Fairchild, H., 1918. Grove Karl Gilbert. Science, 48: 151154. Fenneman, N.M., 1908. Some features of erosion by unconcentrated wash. J. Geol., 16: 746-754. Fenneman, N.M., 1936. Cyclic and non-cyclic aspects of erosion. Science, 83: 87-94. Fenneman, N.M., 1939. The rise of physiography. Geol. Soc. Am. Bull., 50: 349-360. Flemal, R.C., 1971. The attack on the Davisian system of geomorphology: a synopsis. J. Geol. Education, 19: 313. Gilbert, G.K., 1877. Report on the Geology of the Henry Mountains. U.S. Geographical and Geological Survey

D. SACK of the Rocky Mountain Region, Washington, 170 pp. Gilbert, G.K., 1886. The inculcation of scientific method by example, with an illustration drawn from the Quaternary geology of Utah. Am. J. Sci., 31: 284-299. Gilbert, G.K., 1890. Lake Bonneville. U.S. Geol. Surv. Monogr., 1:438 pp. Gilbert, G.K., 1893. Excursion to the Rocky Mountains, physical geography of the region. In: Congres Geologique International, Compte Rendu de la Cinquieme session, Washington, 1891, pp. 261-267. Gilbert, G.K., 1896. The origin of hypotheses, illustrated by the discussion of a topographic problem. Science, 3: 1-13. Gilbert, G.K., 1903, Glaciers and Glaciation. Doubleday, Page & Co., New York. 231 pp. Gilbert, G.K., 1904. Domes and dome structures of the High Sierra. Geol. Soc. Am. Bull., 15: 29-36. Gilbert, G.K., 1905. Style in scientific composition. Science, 21 : 28-29. Gilbert, G.K., 1906a. Crescentic gouges on glaciated surfaces. Geol. Soc. Am. Bull., 17: 303-316. Gilbert, G.K., 1906b. Moulin work under glaciers. Geol. Soc. Am. Bull., 17:317-320. Gilbert, G.K., 1907. The earthquake as a natural phenomenon. U.S. Geol. Surv. Bull., 324: 1-13. Gilbert, G.K., 1909a. Earthquake forecasts. Science, 29: 121-138. Gilbert, G.K., 1909b. The convexity of hilltops. J. Geol., 117: 344-350. Gilbert, G.K., 1914. The Transportation of Debris by Running Water. U.S. Geol. Surv. Prof. Pap., 86:263 PP. Gilbert, G.K., 1917. Hydraulic-Mining Debris in the Sierra Nevada. U.S. Geol. Surv. Prof. Pap., 105:154 pp, Gilbert, G.K., 1928. Studies of Basin-Range Structure. U.S. Geol. Surv. Prof. Pap., 153:92 pp. Gilbert, G.K. and Brigham, A.P., 1902. An Introduction to Physical Geography. D. Appleton and Co., New York, 380 pp. Gilbert, G.K. and Brigham, A.P., 1903. Teacher's Guide and Laboratory Exercises. D. Appleton and Co., New York, 99 pp. Hack, J.T., 1960. Interpretation of erosional topography in humid temperate regions. Am. J. Sci., 258-A: 8097. Hack, J.T., 1975. Dynamic equilibrium and landscape evolution. In: W.N. Melhorn and R.C. Flemal (Editors), Theories of Landform Development. State Univ. New York, Binghamton, pp. 87-102. Harvey, D., 1969. Explanation in Geography. St. Martin's Press, New York, 521 pp. Herries Davies, G.L., 1989. On the nature of geo-history with reflections on the historiography of geomorphology. In: K.J. Tinkler (Editor), History of Geomorphology. Unwin Hyman, London, pp. 1-10. Higgins, C.G., 1975. Theories of landscape development:

HISTORIOGRAPHY OF A PARADIGM CHANGE

a perspective. In: W.N. Melhorn and R.C. Flemal (Editors), Theories of Landform Development. State Univ. New York, Binghamton, pp. 1-28. Hjulstrom, F., 1935. Studies of the morphological activities of rivers as illustrated by the River Fyris. Geol. Inst. Upsala Bull., 25: 221-527. Horton, R.E., 1945. Erosional development of streams and their drainage basins; hydrophysical approach to quantitative morphology. Geol. Soc. Am. Bull., 56: 275-370. James, P.E. and Martin, G.J., 1981. All Possible Worlds A History of Geographical Ideas. Wiley, New York, 2nd ed., 508 pp. Johnston, R.J., 1987. Geography and Geographers - Anglo-American Human Geography since 1945. Edward Arnold, Baltimore, 3rd ed., 304 pp. Judson, S., 1960. William Morris Davis - an appraisal. Z. Geomorph., 4: 193-201. King, C.A.M., 1966. Techniques in Geomorphology. Edward Arnold, London, 342 pp. King, L.C., 1953. Canons of landscape evolution. Geol. Soc. Am. Bull., 64: 721-752. Lawson, A.C., 1915. Epigene profiles of the desert. Univ. Calif. Dept. Geol. Bull., 9: 23-48. Leighly, J., 1932. Toward a theory of the morphological significance of turbulence in the flow of water in streams. Univ. Calif. Publ. Geogr., 6: 1-22. Leighly, J., 1934. Turbulence and transportation of rock debris by streams. Geogr. Rev., 24: 453-464. Marks, E.O., 1913. Notes on portion of the Burdekin Valley. Proc. R. Soc. Qld., 24: 93-102. Martin, L., 1950. William Morris Davis: investigator, teacher, and leader in geomorphology. Ann. Assoc. Am. Geogr., 40: 172-180. Matthes, G.H., 1941. Basic aspects of stream-meanders. Am. Geophys. Union Trans., 22: 632-636. Matthes, G.H., 1949. Solids in stream flow. Am. Geophys. Union Trans., 30:421-426. Mendenhall, W.C., 1920. Memorial of Grove Karl Gilbert. Geol. Soc. Am. Bull., 31: 26-64. Merriam, C.H., 1919. Grove Karl Gilbert, the man. Sierra Club Bull., 10: 391-399. Peltier, L.C., 1950. The geographic cycle in periglacial regions as it is related to climatic geomorphology. Ann. Assoc. Am. Geogr., 40: 214-236. Penck, W., 1924. Die Morphologische Analyse: Ein Kapitel der Physikalischen Geologie. J. Engelhorns Nachf., Stuttgart, 283 pp. Pyne, S.J., 1979. Certain allied problems in mechanics: Grove Karl Gilbert at the Henry Mountains. In: C.J. Schneer (Editor), Two Hundred Years of Geology in

263

America. Univ. Press New England, Hanover, pp. 225238. Pyne, S.J., 1980. Grove Karl Gilbert, a Great Engine of Research. Univ. Texas Press, Austin, 306 pp. Ritter, D.F., 1978. Process Geomorphology. William C. Brown, Dubuque, IA, 603 pp. Ritter, D.F., 1988. Landscape analysis and the search for geomorphic unity. Geol. Soc. Am. Bull., 100:160-171. Rubey, W.W., 1933. Equilibrium conditions in debris ladened streams. Am. Geophys. Union Trans., 14: 497505. Rubey, W.W., 1938. The force required to move particles on a stream bed. U.S. Geol. Surv. Prof. Pap., 189: 121141. Sack, D., 1991. The trouble with antitheses: the case of G.K. Gilbert, geographer and educator. Prof. Geogr., 43: 28-37. Schaefer, F.K., 1953. Exceptionalism in geography: a methodological examination. Ann. Assoc. Am. Geogr., 43: 226-249. Schumm, S.A. and Lichty, R.W., 1965. Time, space, and causality in geomorphology. Am. J. Sci., 263:110-119. Shaler, N.S., 1899. Spacing of rivers with reference to hypothesis ofbaseleveling. Geol. Soc. Am. Bull., 10: 263276. Smalley, I.J. and Vita-Finzi, C., 1969. The concept of "system" in the earth sciences, particularly geomorphology. Geol. Soc. Am. Bull., 80:1591-1594. Smith, W.S.T., 1899. Some aspects of erosion in relation to the theory of the peneplain. University of California, Bull. Dept. Geol., 2:155-178. Stoddart, D.R., 1966. Darwin's impact on geography. Ann. Assoc. Am. Geogr., 56: 683-698. Strahler, A.N., 1950a. Davis' concepts of slope development viewed in the light of recent quantitative investigations. Ann. Assoc. Am. Geogr., 40:209-213. Strahler, A.N., 1950b. Equilibrium theory of erosional slopes approached by frequency distribution analysis. Am. J. Sci., 248: 673-696. Strahler, A.N., 1952. Dynamic basis of geomorphology. Geol. Soc. Am. Bull., 63: 923-938. Tarr, R.S., 1898. The peneplain. Am. Geol., 2 I: 351-370. Tinkler, K.J., 1985. A Short History of Geomorphology. Croom Helm, London, 317 pp. von Bertalanffy, L., 1950a. An outline of general system theory. Br. J. Philos. Sci., 1: 134-165. von Bertalanffy, L., 1950b. The theory of open systems in physics and biology. Science, 111: 23-29. Young, A., 1972. Slopes. Oliver & Boyd, Edinburgh, 288 PP.