The vast majority of national law expositions of the rules for determining when something is a part of land, and therefore partakes in its legal nature, or leads a separate existence in the other category of corporeal property, goods, leaves a distinct impression of a naturalistic approach to the categorisation of property. The view advocated in this study is that the accession or severance of things to and from land as a 'natural scientific enquiry' based exclusively on blends of physical attachment to or socially-expressed intention in respect of land is misleading, or, at least, not decisive. National law accounts of the rules governing the distinction of land and goods need recalibrating to take account of the purpose, or the legal reason, why land is being distinguished from goods in a particular situation. This is well illustrated by the straightforward example of standing timber, variously described doctrinally and in the case-law as integral parts of land, (presently-existing or future) goods, or even the object of 'flying freeholds'. Purpose of classification reveals the many nuances of competing policy considerations and, in turn, better reflects the law as it stands.