Lectures on the History of Moral Philosophy

Rawls organises the lectures around four basic types of moral reasoning: perfectionism (Leibniz), utilitarianism (Hume, in Rawls's reading), intuitionism (Clarke and Price), and Kantian constructivism . This taxonomy is not a neutral survey device; it reflects Rawls's own philosophical commitments. He treats Kantian constructivism as the most defensible position and reads the other figures as establishing the problems Kant answered or as offering alternatives that fail on their own terms. The lectures on Hume, for instance, are shaped by the question of whether a desire-based psychology can yield a conception of practical reason—a question Rawls answers in the negative . The framework thus makes the volume as much a statement of Rawls's own view as a history of moral philosophy.

Herman edited the volume from Rawls's lecture notes, which were prepared and updated by Rawls or his assistants and made available privately to students from the mid-1970s through 1991 . She added two lectures on Hegel based on Rawls's personal notes, completing the volume's trajectory from Hume through Kant to Hegel's critique . The book includes an editor's foreword, a note on the texts, and a course outline appendix . Readers should treat the volume as a curated reconstruction of a course that Rawls taught for decades, not as a monograph he wrote for publication. The lectures were compiled in 1991 after the final of four major revisions, and Kirkus noted they reflect years of careful editing and rewriting .

Rawls reads the categorical imperative as a procedure for generating substantive moral conclusions, not merely a formal consistency test. He describes it as a 'selection device . . . like a mathematical function' and admits that he has 'played down the role of the a priori and the formal' and given what some may consider 'a flat reading' of the imperative . This is the constructivist Kant: the moral law is not discovered as an independent order of values but constructed through a procedure of practical reasoning. Rawls's reading connects the lectures directly to his own work, particularly the Dewey Lectures on Kantian constructivism, which are reflected in the sixth Kant lecture . Readers familiar with A Theory of Justice will recognise the original position as a descendant of this procedure.

James King, reviewing the volume in Hume Studies, identified 'two Rawls' at work in the Hume lectures: 'one the engaging commentator, the other the Kantian polemicist' . The polemicist portrays Hume as the brilliant but misguided thinker who set the problem Kant solved, and concludes that Hume 'does not have a conception of practical reasoning' . The commentator, by contrast, offers illuminating readings of Hume's texts—on justice as an artificial virtue, the judicious spectator, and the is/ought passage . King's assessment is that the treatment is 'far from bleak overall' and shows Rawls to be an avid reader of the Treatise and its secondary literature, even if the Kantian framework shapes what he finds and misses.

The Hegel lectures close the book and were added by Herman from Rawls's personal notes, since they were not part of the standard course packet . Their function is to present Hegel's critique of Kant, which Rawls treats as a serious philosophical challenge rather than a mere historical curiosity. Kirkus noted that readers interested in Rawls's ideas on social and economic equality, liberalism, and the possibility of justice should be particularly glad for the Hegel lectures focusing on his critique of Kant . The Hegel material extends the volume's arc: Hume sets the problem of practical reason, Kant constructs the solution, and Hegel presses the question of whether Kant's moral subject is too abstract to sustain ethical life. The lectures are brief relative to the Kant section but complete the course's narrative.

The volume is demanding but not closed to newcomers. Rawls's pedagogy is patient and generous—Kirkus described him as teaching 'from the position of a kind of master student,' acknowledging the difficulty of the texts without talking down . The Kant lectures, which constitute roughly half the book, walk through the Groundwork and the second Critique in detail. However, Rawls's constructivist reading is not the only plausible interpretation of Kant, and readers without any background may struggle to see what is at stake in his departures from more traditional readings. The Hume and Leibniz lectures are more self-contained. Harvard University Press's own description notes that the volume offers 'probing discussions' that are 'sometimes challenging' . Beginners should pair the lectures with a standard commentary on Kant's ethics.