The evidence that proponents of the reform theory have cited most often in support of their position consists of statements in the Tallaght memoir expressing céli Dé displeasure with the state of discipline in other churches. D.A. Binchy was the first to call attention to a couple of passages in The Monastery of Tallaght which show the ‘obvious disapproval’ of céli Dé of their religious contemporaries. It was clear to him that the céli Dé ‘movement’ was ‘a sharp reaction against the laxity and corruption of the older monastic foundations’. Binchy was followed by Kathleen Hughes, who was no less confident that ‘the Culdees certainly regarded themselves as reformers’. Upon considering other passages from the Tallaght memoir comparable to those Binchy cited, she remarked,

Peter O'Dwyer, who relied upon Binchy and Hughes, similarly detected ‘a certain enmity between Maeldithruib and the members of the old churches who had not performed their duties properly’. For these scholars and many who followed them, the evidence of the Tallaght memoir demonstrates that Mael Ruain and his associates perceived themselves as reformers at a time when the older monastic foundations in Ireland had grown lax and corrupt. To this evidence we now turn.