Kinds and problems of geomorphological explanation

What characterises satisfactory explanations in geomorphology is a key methodological question deserving continued analysis. In turn it raises the issue of the role played by methodology within the science. At its best, methodology can provide helpful distinctions, identify key issues and yield guidance for researchers. The substantive context for debates on explanation is the apparent complexity and difficulty of geomorphology as a science, which is arguably no greater than that of other Earth or environmental sciences. The logical view of explanation dominant in the 1950s and 1960s still has value, but a broader view is needed of explanations, related to the questions geomorphologists (and others) ask and to the answers that they find interesting. Answers may be sought in terms of purpose, history, mechanisms and statistics. Arguments over what is supposed to be reductionism can be clarified by underlining that both micro- and macro-explanations may be helpful. Although many geomorphologists aspire to mechanistic explanations, they often stop short at statistical explanations, making use of convenient functional forms such as power laws. Explanations have both social and psychological dimensions, the former much stressed in history of science and recent science studies, the latter deserving greater emphasis at present. Complicated models raise the question of how far it can be said that geomorphologists understand them in totality. A bestiary of poor explanations is needed, so that geomorphologists are not seduced by weak arguments and because they often serve as steps towards better explanations. Circular arguments, ad hoc explanations, and mistaking the name of the problem for the solution are cases in point.