In historical studies of political thought, there is often an intimate connection between the choice of textual subject matter for investigation and the interpretive approach deployed by the scholar. This connection is explicit in Thomas W. Merrill’s rich and insightful study, Hume and the Politics of Enlightenment, which aims to glean an account of politics and morality—as well as an account of the appropriate philosophical approach to questions of politics and morality—from the writings of David Hume. Part of the charm of the book is the apparent seamlessness between subject and author: It is never clear exactly where Hume ends and Merrill begins, with the latter offering an interpretive reconstruction of the former’s theory that is consistently sympathetic, and yet expressed in a gentle, reflective, and never over-bearing, manner. As with the Humean position being outlined, Merrill’s interpretation is appropriately free of any philosophical or methodological zealotry.

Merrill begins with the worry that the contemporary status of philosophy—understood as “radical questioning”—is politically troubling, since it appears to have given rise either to disastrous forms of anti-liberalism (attributed to the legacies of Martin Heidegger and Karl Marx), or to the alleged defeatism of Richard Rorty’s relativism (pp. 1–4). His thought is that that Hume’s philosophy has something to say to profitably address this impasse. Even if Merrill does not expect it to yield any absolute normative conclusion, his study is “by no means merely antiquarian in intention” (p. 7). Indeed, the hope is that an interpretive conversation with Hume could liberate us from dominant ways of framing our moral/political problems, such that we might “come to see our situation with new eyes” (p. 8, 191). This refreshingly open-minded attitude to the philosophical value of scholarship in the history of political thought is attractive, and puts less pressure on the concern about the (totalitarian or defeatist) culs-de-sac that radical questioning has allegedly led us down so far, an idea that remains too undeveloped to do much work.

As with many modern scholars—but famously unlike Hume’s contemporaries—Merrill here gives priority to the A Treatise of Human Nature, rather than either of the Enquiries or the major writings on history or religion. The scope of the study is limited in that sense, and also insofar as it “in no way attempts to replace the variety of interpretations of Hume that exist” (p. 11). It is nevertheless notably ambitious in two respects: First, in its attempt to read the Treatise as offering a profound answer to the perennial question about the capacity of philosophy to contribute to politics and morality; and, second, in its claim that a proper understanding of Hume’s answer to this question requires attention to an oft-overlooked allusion to Socrates in the Treatise, where the need to “call philosophy down from the heavens…and compel it to inquire into life and mores and good and evil things” is expressed (p. 7).

The methodological tone struck by Merrill throughout the book is also admirably undogmatic, though notably he does lean on some well-established Straussian interpretive strategies. For example, some of his claims do not exactly depend on, but are assisted by, assumptions about the “structure of the Treatise” as a key to its meaning, such as the precise positioning of the Socratic allusion (p. 17, 35) in the conclusion to Book I, or the textual ordering of Hume’s Essays (p. 186). There are also claims about authorial intentions that are somewhat overplayed in a manner invited by some of Strauss’s methodological writings. Merrill thus refers to “the fact that Hume had to downplay, disguise, or downright lie about his heterodox views” about religion (p. 10), and yet—whatever the status of Christian orthodoxy in Britain at his time of writing—it is certainly not a fact that Hume had to do any such thing. Nevertheless, on the whole, the book actually emerges as a fine exemplar of just how fruitful some Straussian tropes can be when treated as useful heuristics rather than as hard rules for interpretation.

Merrill argues provocatively that Hume’s Socratic allusion holds the key to understanding the entire intellectual project of the Treatise: It expresses the view that philosophers must enter “into an alliance with ordinary citizens” (p. 26), rather than seek any other-worldly detachment in their reasoning, and should conceive of enlightenment as the self-awareness that emerges through a questioning activity that takes popular opinion seriously instead of attempting to stand above it. Although it might seem far-fetched to place such interpretive weight on a single remark, through an impressively dogged and detailed analysis, Merrill shows how his reading makes sense, and how it inspires Hume’s conception of enlightenment as an ultimately personal project of self-understanding that is nevertheless bound up with a distinct political vision.

Each chapter offers textually scrupulous, penetrating analyses of Hume’s idea of enlightenment and its consequences for the relationship between philosophy and politics. Following a detailed discussion of the Socratic allusion, the second chapter skilfully explains both the grounds of his “seeking” rather than “destructive” scepticism in the Treatise (p. 58) and his turn towards “human nature in all its manifestations” as the gateway to proper philosophizing (p. 60). The third and fourth chapters cover the best-known aspects of Books II and III of the Treatise, such as Hume’s view of moral psychology and motivations, and his ideas about justice, rights, and the status of the virtues. Throughout these discussions, Merrill displays a thorough command of Hume scholarship, and is carefully attuned to various interpretive debates over the identity of his moral thought, though most of the direct critical engagement with other commentators is confined to the footnotes.

After guiding us carefully through the Treatise, Merrill then spends the final two chapters connecting its concerns with those of Hume’s Essays, Moral, Political, and Literary. These are perhaps the most original and compelling sections of the book, where we see the normative political payoff of Hume’s idea of enlightenment. Merrill explores the philosophical roots of Hume’s critique of religion, which is ultimately really only a “symptom” caused by an erroneous commitment to philosophical truth, one that views “the Platonic philosopher-king [as] the appropriate model for political society” (p. 146).

The normative vision that then emerges is of political liberalism and philosophical pragmatism. Within Hume’s thought, the securing of individual liberty takes priority. For him, the fact that wise laws and political institutions are the best way to protect individual freedom implies the rightness of republican government (pp. 137–138), because it secures the rule of law that is, in turn, necessary to enable commerce (p. 147). In order for the liberal commercial republic envisioned to flourish, it needs also to be cherished by the very middle-class individuals whose creation it assures (pp. 169–171). And, crucially, as Merrill emphasises, these are the very “honest gentlemen” whose opinions Hume thinks must be the starting point for meaningful philosophical reflection, and consequent self-knowledge, in the first place. The unpacking of a coherent theory across the Treatise and the Essays is another virtue of this valuable addition to Hume scholarship, which illustrates just how philosophically illuminating the historical analysis of political thought can be.