The earliest evidence with regard to Buddhist doctrine (and literature) which can be dated precisely and reliably are the inscriptions of Aśoka, who expressly declares himself a lay follower (upāsaka) of Buddhism and specifically addressed himself to the Buddhist Order in two of his edicts. It is therefore reasonable to reconsider this evidence as to its bearing on the date of the Buddha, in the hope of discovering clues to either a longer or a shorter or even no interval between the origins of Buddhism and the time of Aśoka.

In: Heinz Bechert (ed.), The Dating of the Historical Buddha / Die Datierung des historischen Buddha, Part 2 (Abhandlungen der Akademie der Wissenschaften in Göttingen, Philologisch-historische Klasse, 3. Folge, Nr. 194), Göttingen 1992, 110–147.