PHYSICAL geographers traditionally have avoided introspective philosophical analysis of their scholarly activities. This situation contrasts sharply with the fierce philosophical debate among human geographers during the past fifteen years (Smith 1979; Walford and Gregory 1989; Johnston 1991). The primary purpose of this article is to persuade physical geographers of the virtue of engaging in philosophical introspection; however, it is important to recognize that physical geography is as diverse as human geography. This essay focuses specifically on the potential contribution of philosophical analysis to geomorphology, but it also informs other sub fields of physical geography, because the issues discussed are central to all branches of the physical sciences.
The reason for the neglect of philosophical issues by geomorphologists is unclear. Perhaps it reflects a basic sense of philosophical security. Although the issue of whether geomorphology should be regarded as scientific or historical has been somewhat controversial, much of this discussion has occurred within geology, not geography (Simpson 1963; Watson 1966, 1969; Kitts 1977; Baker 1988; Baker and Twidale 1991). Contemporary geographical geomorphologists appear to be fairly secure in their role as physical scientists, a view that is reinforced by continued emphasis on the dichotomy between human and physical geography. Thus they may be confident that geomorphology is firmly rooted in established philosophical foundations of physics and chemistry. In other words, as physical scientists their philosophical underpinnings are incontrovertible, a perspective strengthened by the limited exposure that many geomorphologists have had to the philosophy of science.
Geomorphologists generally receive little, if any, formal training in philosophical topics at the undergraduate or graduate level. Moreover, in many cases what little training they do receive often comes from human geographers, who simply inform the physical geographers that they are empiricists and then proceed to survey the myriad philosophical perspectives in human geography. As a result most geographical geomorphologists have perfunctorily embraced either logical positivism (Harvey 1969) or critical rationalism (Haines-Young and Petch 1986). These philosophical perspectives generally are erroneously portrayed as equivalent, except for a minor difference in method: logical positivists attempt to verify hypotheses, but critical rationalists try to falsify them (Johnston 1991, 72). One purpose of this essay is to illustrate to human and physical geographers alike that the philosophy of the physical sciences, including geomorphology, is not as secure or uncontroversial as it may seem.
Even if the philosophical foundation of the physical sciences is controversial, this situation may not trouble geomorphologists for two reasons. First, they may presume that any debate about philosophical issues concerning the physical sciences should focus on physics or chemistry, not geomorphology, which is derivative from fundamental sciences. This view is misguided because geomorphology as a science deals with distinctive types of complex, unconstrained natural systems that differ from those investigated in laboratory sciences and in many cases uses methods that vary from those employed in laboratory investigations. It is therefore uncertain that philosophical arguments developed for physics and chemistry directly inform geomorphology. Second, some geomorphologists probably perceive philosophy as an esoteric, unnecessary endeavor that has little relevance for practicing scientists. Although occasional forays into philosophy are necessary for well-rounded scientists, to delve too deeply into such issues often is regarded with suspicion, if not outright contempt, and is sanctioned only if the primary purpose is to seek methodological guidance rather than philosophical insight. This disparaging attitude reflects a basic misunderstanding of the relationship between science and the philosophy of science. …