 Statements such as these have a strong historicist flavour. This ambiguity exposes a tension between two different conceptions of the role of philosophical analysis. On the first conception the task of philosophy is to delineate the subject matters of different forms of knowledge and denounce the encroachment of one form of knowledge on the subject matter of another. The emphasis is on explanatory pluralism, not historical relativism. The defence of the autonomy of historical explanation in The Idea of History, for example, implies that the role of philosophical analysis is to identify the distinctive presuppositions of history and to distinguish them from those of natural science with a view to combating scientism. The second conception, by contrast, places the emphasis on historical relativism rather than explanatory pluralism. It is this second conception of the role of philosophical analysis in An Essay on Metaphysics that has led to the view that Collingwood’s later metaphilosophy differs substantially from his earlier view of the role of philosophical analysis, a view sometimes referred to as “the radical conversion hypothesis”. The hypothesis of a historicist turn was first advanced by Malcolm Knox in the editorial introduction to the posthumously published The Idea of History. It was also endorsed by early commentators such as A. Donagan (1962 and 1972), Toulmin (1972) and N. Rotenstreich (1972). The expression “radical conversion hypothesis”, however, was actually coined by Rubinoff (1966) who alongside Mink (1969) rejected it as an inadequate description of Collingwood’s position. This is still a live debate in Collingwood scholarship, although more recent studies (Martin 1989; Modood 1989; Connelly 1990; Oldfield 1995; Beaney 2005; D’Oro 2002, 2010) tend to emphasise the unity rather than discontinuity in Collingwood’s metaphilosophical approach.