In question commentaries on Priscian and Aristotle, scholastic authors from the thirteenth and fourteenth centuries discuss whether language is innate in humans, so that a person can acquire a language without the normal learning process. Commentaries on De sensu et sensato are a particularly rich source of discussions of the problem, because Aristotle there seems to assume that congenital deafness automatically implies dumbness. Generally, the scholastics conclude that no existing language is more natural than any other, and that a normal learning process is required for anyone to acquire one of the established languages. But they also consider the possibility that a couple of children who were brought up without hearing any human language (King Psammetichus' experiment) would develop a language of their own, thus satisfying their inborn urge to communicate.