German Indologist Theodor Bloch (1894) dismissed the medieval Prakrit grammarians as unreliable, arguing that they were not qualified to describe the language of the texts composed centuries before them. Other scholars such as Sten Konow, Richard Pischel and Alfred Hillebrandt, disagree with Bloch. It is possible that the grammarians sought to codify only the language of the earliest classics of the Prakrit literature, such as the "Gaha Sattasai". Another explanation is that the extant Prakrit manuscripts contain scribal errors. Most of the surviving Prakrit manuscripts were produced in a variety of regional scripts, during 1300-1800 CE. It appears that the scribes who made these copies from the earlier manuscripts did not have a good command of the original language of the texts, as several of the extant Prakrit texts contain inaccuracies or are incomprehensible.