Rawls’s mature works treat the topic of Catholicism only in a few brief passages and several extended footnotes. Yet his view of the Catholic Church – its history, institutional structure, doctrine, and social teaching – seems to have inluenced his thinking at several points, particularly his understanding of political liberalism and public reason. It is noteworthy that one of the very few interviews given by Rawls, and the only one published in his Collected Papers, appears in the Catholic magazine Commonweal, where Rawls discusses (with Bernard Prusak) the relationship between religion and liberalism (CP 616–622).

In the terminology of political liberalism Catholicism is a comprehensive religious doctrine – it is connected to a recognizable tradition of thought and involves the exercise of both theoretical and practical reason to address the major aspects of human life (PL 59, 175; JF 14). Depending on how it is interpreted, Catholicism may be afirmed reasonably or unreasonably (PL 60 n.14). Among their other features, reasonable comprehensive doctrines should acknowledge the burdens of judgment and key liberal-democratic political values and commitments (JF 191; BIMSF 267). Especially in its refusal to join forms of comprehensive liberalism in celebrating moral autonomy as a central value (PL xliii), Catholicism is precisely the kind of worldview addressed by the fundamental question of political liberalism, namely, how those who afirm a religious doctrine based on religious authority might also accept democratic rule guided by a reasonable political conception of justice (PL xxxvii).