AbstractThis note seeks to analyse P. Tzamalikos arguments, contained in two recently published books, on Cassian the Sabaite – supposedly an early Christian author whose figure was later eclipsed by that of John Cassian of Marseilles. Tzamalikos argues John Cassian is a medieval forgery and likely never existed, and that this is evinced by a ninth century Greek manuscript containing a portion of the Conlationes patrum. A careful reading of his ar- guments suggests it is however still too difficult to prove the existence of the new Cassian and, above all, to dismiss the known Cassian of Marseille. Tza- malikos has preferred not to make a close study of the two versions of Cas- sian’s texts (Greek and Latin), but has only dismantled indirect and external evidence of what he supposes was a large forgery project. Furthermore, what Tzamalikos argues for is far from being definitely proven. A further critique of his thesis recognizes three main issues with his argument: 1. The Greek manuscript was published for the first time in 1913;; 2. The entry entitled Cassianus natione Schyta in Gennadius’s catalogue cannot be considered a later interpolation;; 3. The Contra collatorem by Prosper of Aquitaine fur- thermore provides strong evidence that Cassian’s texts has been written in Latin at the beginning of the fifth century.