"Japanese Buddhologist Kogen Mizuno argues in his "Buddhist Sutras" (1982) that the material we possess may not contain the actual words of the Buddha because "they were not recorded as he spoke", but compiled after his death and also because they do not survive in the original language (some form of Magadhi Prakrit) but "transmitted in other Indic languages of later periods, and without doubt conscious and unconscious changes in the Buddha's words were made during several centuries of oral transmission.