The article presents a methodological proposal, inspired by the concepts taken from “Political Liberalism” of John Rawls. The purpose of the article is to employ Rawlsian concepts of “public reason” and “social reason” to examine the reasonableness of positive law, i.e. the vision of fundamental justice and the concept of the general good that are manifested in law. The legislative process is seen as a kind of filter for contents representing the so-called background culture transferring it partly to the public reason. The examination of the reasonabless of positive law allows to check whether the law of a democratic community really reflects its goals, visions of the general good and values, or contradicts them. The presented methodology assumes a correction of the Rawlsian individualist vision, by distinguishing three models of reasonableness of law present in contemporary democracies and corresponding to three ways of understanding basic justice and the general good, i.e. the individualist, communitarian and collectivist model.