He conducted post-doctoral research in Munich and Frankfurt with Jürgen Habermas as a Von Humboldt Fellow and then at Berkeley again (1989), leading to the publication of his first book, Modernity and Authenticity.

Ferrara's work revolves around an account of normativity centered on authenticity and exemplarity, which incorporates a reconstructed version of Kant's “reflective judgment” and is intended as an alternative both to proceduralist, neo-transcendental approaches to validity and to anti-normative, radical contextualism.

In The Force of the Example (2008), drawing on Kant's Critique of the Power of Judgment but also on Arendt, Rawls, Dworkin, and Habermas, Ferrara applies his view of exemplary validity to central themes of contemporary political philosophy, including public reason, human rights, radical evil, sovereignty, republicanism and liberalism, as well as religion in the public sphere.

A Dialogue on Political Liberalism (2021), co-authored with Frank I. Michelman, addresses the implications of Rawls’s “liberal principle of legitimacy” in three areas: the tension between government by the people and government by consent; the ensuing challenges for judicial treatments of constitutional law; and the magnification of these tensions and challenges when transnational legal ordering comes under consideration.

Rawls’s view of constituent power is reconstructed as bound by the standard of “the most reasonable for us” and as cutting across Kelsen's and Schmitt's paradigms.