Nature - autonomous learning

206 the dis/unity of geographyat one spatio-temporal scale may not hold true at a higher or lower one.Here each strata of biophysical reality is composed of, but not reducibleto, entities that exist at smaller scales. In a classic paper, Schumm and Lichty(1965) implied that stratification was part and parcel of the world thatphysical geographers study. They argued that the dependent and independentexplanatory variables changed depending on the spatio-temporalscale in question (see Table 4.1). Four decades on, physical geographersremain uncertain how far analyses conducted at one scale are applicableto other scales. Many engaged in small-scale research into environmentalprocesses have tried to upscale their findings. But, as Stephan Harrison(2001) argues, this is implicitly reductionist ontologically speaking. Thatis, it suggests that ‘the real essence of an object of inquiry can be seen atthe microscopic “fundamental” scale’ (2001: 330). In the words of anothercommentator, ‘Reductionist studies . . . have become the modus operandiof much scientific research [and] often take place at very detailed spatialand temporal scales. Reductionism functions by studying small systems indetail in order to aggregate the information . . . about a broader system’(Barrett 1999: 709). Against this, it is possible to argue that larger-scaleenvironmental phenomena have so-called ‘emergent properties’ that cannotbe ‘read off’ from the properties that exist at smaller scales. For instance, ifone wants to know why mountain ranges form over long time-periods isit necessary to understand the molecular properties of all the rock types inthose ranges? Some would say not. The debate over stratification andreductionism remains ongoing and unresolved. It is, as Sudgen et al. (1997:193) aver,‘a nut that must be cracked’ (see Burt 2003b).Second, there has been a related debate over whether physical geographersstudy so-called ‘natural kinds’ or not.A natural kind is any element of the realworld that is possessed of the following two qualities. First, it is ontologicallydifferent and distinct from other elements (even though it may be relatedto those other elements in practice). Second, it retains its physical integrityregardless of the specific circumstances in which it exists.Thus, a piece ofgranite might be considered a natural kind if it can be shown that it isunlike (qualitatively different from) other kinds of rock and that it remainsgranite whether it is found on a scree slope or at the bottom of the ocean.It is often said that the ‘hard sciences’ (like physics) study natural kinds:that is, the basic ‘building blocks’ of the biophysical world. But does a fieldscience like physical geography study natural kinds too? The Activity onpage 209 invites you to construct an answer to this challenging question.