In the section of The Idea of History entitled "Epilegomena 2: The Historical Imagination," R.G. Collingwood propounds his theory of the criterion of historical truth. All theory entails ontological commitment to those principles and concepts on which its truth relies. In Collingwood's case, these include the historical or a priori imagination, the concept of necessity, the idea of the past as an innate idea, a coherence theory of truth in the project "to construct a picture of things as they really were and of events as they really happened," and an elastic notion of evidence, according to which the present, as sequel to the past, serves as evidence for the past. Each of these commitments succumbs to challenges to its validity, plausibility, and applicability. As a result, the very notion of a criterion of historical truth, as Collingwood formulates it, collapses. The a priori imagination lacks any point of epistemological purchase and becomes a faculty with nothing to address since, in applying this concept, Collingwood confuses the distinction between a priori and a posteriori knowledge as well as that between a priori and inferential reasoning, converts historical contingency into necessity, and misconstrues the notion of synthesis or the combination of disparate units into a systematic whole. Moreover, through his linking of evidence with temporal becoming, truth loses its stable meaning as perspective on evidence changes with each new moment, as does the evidence itself.
