Nature - autonomous learning

202 the dis/unity of geographydynamists used several strategies to ‘protect’ their perspective.One of these was to cast doubt on the credibility of the stabilists’evidence. For instance, one piece of evidence related to volcanic ashwhich had, apparently, remained relatively undisturbed throughthe Pliocene, casting doubt on the dynamists’ ideas of major environmentalchange in the region. In response, Sudgen (1996: 499)reports two dynamists casting around for reasons to dispute theapparently indisputable, suggesting that the ash deposits may overlaytill that had been moved during a melting phase. Overall, Sugdenshows that intellectual disputes in physical geography are not cleanlyresolved by recourse to ‘the facts’. Instead, often entrenched perspectivesprove difficult to alter because researchers have investedtime, money and their reputations in developing them.UNDERSTANDING BIOPHYSICAL REALITY:SOME KEY DEBATESWhile most physical geographers express faith in the rigour of theirinvestigative procedures, this is not to suggest that they share the sameepistemological and ontological beliefs. It is one thing to assume thatthere is a ‘biophysical reality independent of the human mind’ (Phillips1999: 7). But it’s quite another to agree on how, broadly speaking, wecan come to know that world and how, broadly speaking, that world isstructured. All researchers – physical geographers or otherwise – haveontological and epistemological beliefs (as indeed do all people: see Box4.4).These beliefs form the context for the investigative steps discussedin the previous section. They are, if you like, a researcher’s ‘bedrockassumptions’. Ontological beliefs are general beliefs about what is real (orwhat exists). Epistemological beliefs are general beliefs about how we, ashumans, can come to know reality. Though I’ve not used the term thusfar, I’ve already explained that most physical geographers are materialists inthe ontological sense. That is, they believe in the existence (or reality,hence the term ‘real’) of a physical world independent of, or at leastirreducible to, any given set of human perceptions of or actions upon thatworld. But not all materialist ontologies are the same, as we’ll see below.