One of the critiques deliberative democracy theorists usually make to aggregative understandings of democracy – among which they include direct democratic mechanisms such as those implemented in Switzerland – is that they only take the procedure into account and dismiss all challenges to its outcomes as “undemocratic” (Cohen 1997, 431; Gutmann and Thompson 2009; Manin 1987). In Joshua Cohen’s view, democracy should allow for controlling the substance of the outcomes. However, a closer analysis of his argument reveals that all the limitations to the possible outcomes are set by the procedure itself. This paper thus first argues that Cohen’s definition of substance offers an opportunity to reconsider the Swiss institution of the facultative referendum as a way to implement his “three principles” (Cohen 1997). In a second step, it questions whether the principled defense of this institution in the Swiss context calls its capacity to create democratic legitimacy into question.