This article compares public debt as it is concived by Saint-Simonians, Liberal economists and Socialists. I endeavour to analyse public debt through its capacity to modify or preserve social order. Armed with financial science, the Saint-Simonians wished to use public borrowing as a means for enabling the development of the industriels. Liberal economists condemned the development of public borrowing with advocating teachings of political economy. Against these two theories of public debt, the 1840s Socialists proposed an analysis based on social classes and concluded that public borrowing was unable to structurally modify the social antagonism of the nineteenth century society.