 Rousseau’s views on the expressive power of music are further elaborated in his Essay on the Origin of Languages (1781), in which he argues that music and natural languages developed out of a common source, a language used for the expression of feelings (Rousseau 1781: chapter XII, “Origin of music”; see Thomas 1995: chapter 5). Following this common origin, both language and music underwent a process of decay. Languages developed in order to communicate increasingly complex thoughts, but lost expressive power, especially after the emergence of writing (Rousseau 1781: chapters V–VI). Thus, Plato’s Greece, Rousseau states, had no shortage of philosophers, but lacked musicians (Rousseau 1781: chapter XIX). Regarding this remark, Martinelli (2012 [2019: 62]) observes: