‘The rocks do date the fossils, but the fossils date the rocks more accurately. Stratigraphy cannot aid this kind of reasoning if it insists on using only temporal concepts, because circularity is inherent in the derivation of time scales.’

J.E. O’Rourke, ‘Pragmatism versus materialism in stratigraphy’. American Journal of Science, vol. 276, January 1976, p.53.