Though it is the science of modern societies, sociology has for some time taken a critical and sceptical stance with regard to the development of democracy; yet democracy is the regime par excellence of modern society. This article examines this issue by drawing out the complexity of the relationship between sociology and democracy. This reading reveals that, above and beyond its scepticism of democracy, sociology discloses the double nature of the modern subject, simultaneously an autonomous subject and a social subject. It is by fully assuming the double nature of the modern subject that sociology will succeed in becoming the discipline par excellence of contemporary societies, which have also become hosts to radical democracy.