 After a phase in which the language of action had been fruitfully combined with the language of articulated sounds, different elements of this mix began to develop autonomously. They also recombined later in various guises. On this basis, Condillac attempted to account for the development of arts and forms of expression such as music, dance, theatre, poetry. For example, the language of action can dispense altogether with sounds of any kind, while extending the range of its expressive gestures: already impressed by accounts of ancient pantomimes, Condillac saw this point confirmed by the modern development of the language of signs for deaf-and-dumb people in the school of the Abbé de l’Epée (Essay II.i.4, Grammar I.1). By developing only the tonal part of the sounds, the language of action can turn into music, unaccompanied by any words and gestures (Essay II.i.5).