Aaron Zubia has written the next great book on David Hume. The conventionally-titled book—The Political Thought of David Hume: The Origins of Liberalism and the Modern Political Imagination—is unconventional in its framing, brilliant in its methods, morally serious in its ambitions, and deeply philosophic in its orientation. Hume illuminates the crisis of liberal modernity—and Zubia spreads breadcrumbs to follow for people looking for a way out.

Very ancient Epicurean insights are built into the foundation of Hume’s modern thinking. Those pretenses to knowledge are limited to what could be sensed or experienced; that (therefore) human beings are forever consigned to ignorance and fancy when it comes to understanding the gods or God; that the world itself is disenchanted or at least, as Zubia puts it, “despiritualized”; that religion is the “enemy to knowledge, happiness, and social order”; that morality and politics begin with universal agreement or conventionalism; that the human good is pleasure, though it may be refined beyond simply bodily pleasure; that human society advances from barbarism to civilization—these and more ideas from Epicurus are fundamental tenets in the modern political imagination.

Yet a deep difference between Hume and the ancient Epicureans remains. Epicurus and his followers thought their premises pointed people away from politics and toward a serene acceptance of the world as it was. The goal was tranquility. Hume, in contrast, turns Epicurean premises toward destroying certain mores and institutions (i.e., the church, feudalism, mercantilism) and toward creating other mores and institutions (i.e., the politics of humanity and modern commercial republicanism). Hume’s is a modern Epicureanism, readied for political action and purposed to serve as the basis of a new public philosophy. He embraces this transformative stance with more philosophic equanimity and less fanaticism than most other moderns (which attracts conservatives to Hume), but Hume’s equanimity has its limits.

Hume’s most explicit departure from ancient Epicureans deepens his radical adherence to Epicurean conventionalism. Epicureans were, from Hume’s perspective, hopelessly metaphysical, in that they made dogmatic claims that the universe was nothing but matter in motion. Hobbes followed Epicureans on precisely this point. For Hume, however, human beings can never really know what the fundamental stuff of nature really is. Books containing such “school metaphysics” should be committed “to the flames,” as Hume writes in the final words of the first Enquiry.

This alienation from nature, at the root of Hume’s vaunted skepticism, elevated the importance of human agreement about what people will say about nature. Human beings must turn to custom as “the great guide of human life,” as Hume writes. People construct customs through universal agreements or conventions. In science, this agreement allows common action to confront the realities of raw nature. In politics and morals, this agreement puts an end to disorder and begins the reign of law and justice that, eventually, leads to refinement and progress.

This conventionalism is the effectual truth of Hume’s deep agreement with the social contract tradition, despite Hume’s reputation as a critic of that tradition. For Zubia, Hume shows that the social contract does not really explain why people obey government, but Hume is nonetheless a contractarian because he thinks universal agreement about moral conventions is the origin of justice and morality. Hume naturalizes the social contract and its standards emerge through slow evolution. Hence, he deepens the influence of conventions on the human mind by articulating the agreement on the goals of society that all will agree are useful to pursue.

Zubia presents his conclusions about Hume’s modern Epicureanism with brilliant methods. In his own day, the Epicurean and atheist Hume faced serious critics, many all but forgotten today. Zubia uses the writings of Hugh Blair, Richard Bentley, Alexander Carlyle, and a chorus of others to show that Hume’s Epicureanism was the basis for many complaints about his orientation. In one sense, who cares what these relative nobodies thought? In a deeper sense, however, these “nobodies” become somebodies who defended Stoic philosophy and Christian faith in Hume’s own time. They aren’t Cicero or St. Augustine, but they aren’t nobodies either—they carried the ideas of the Great Tradition into Hume’s day and laid bare the radicalness of Hume’s Epicurean premises.

This turn to secondary thinkers sharpens the moral stakes in Hume’s very controversial teachings. Embracing the Epicurean account means rejecting Stoicism and Christian transcendence. Epicureanism is not neutral, after all, so it must be guarded and guided through careful philosophical statesmanship. Such statesmanship sometimes means, as Zubia shows, heaping scorn upon religious tenets and ways (which Hume does in spades), but it also means popping the bubbles of parties based on “abstract speculative principle” and exposing faux arguments reinforcing political tenets like passive obedience, the divine right of kings, and the Whig theory of history. All of this directs politics toward habitual acceptance of political conventions that work to promote certain ends. Epicurean radicalism fosters a simulacrum of political conservatism.

In this, Zubia shows that Hume’s interventions into politics almost worked too well. What Hume saw as highly contestable, his epigones like John Rawls accepted dogmatically and applied, with selective zeal, to demand (or achieve) even greater conformity. Rawls almost appears as the effectual truth of Hume’s Epicureanism. If you want constructivism and conventionalism, if you want the dominance of “public reason,” if you want the basis of controversial “comprehensive doctrines” forgotten—Rawls is the man. Rawls imagines that a “strictly political” conventionalism is possible, but every great thinker, including Hume, of course, knows that philosophic concerns about the goodness of conventions from the picture persist. Hume may have thought that reason itself could not guide people through the thicket of pluralism, but he thought there was a guide grounded in correct feeling. Rawls’s unwillingness to let himself see what all he had seen before leads to—in Zubia’s most strident formulation—“the tyranny of ‘public reason’ liberalism.” Hume nodded toward, but hardly endorsed, such a tyranny.

As critics dogged Hume in his day, it is natural to wonder whether they were right. Zubia raises this philosophically ambitious question in the concluding substantive chapter, where Zubia and “the nobodies” speak on behalf of the Great Tradition. Hume reduced reason to a species of feeling, while denigrating reason as logos through which people reason about the ends of human longing. Hume’s “nobody” early critics consistently raise the issue of conscience, the touchstones of moral actions, and man’s natural duties (what C. S. Lewis calls the Tao in his classic The Abolition of Man) as windows into the world of human life. Is stealing or tyranny simply unjust by convention? Is there a backbone of truth or natural right within the soft tissue of convention, giving it some shape and causing no little wonder? The existence of natural right would then be suggestive evidence that the Christian tradition itself might explain why human beings long for righteousness. If critics are “right that there is some natural order that human beings can recognize, that guides them in their pursuit of good and avoidance of evil, then there must be a source of that order, a higher intellect, lawmaker and judge,” Zubia writes near his conclusion. Zubia puts Hume’s Epicureanism in the dock, to show that it might be a merely political doctrine just like Rawls’s political liberalism.

Epicurus’ system was not the final word about human life, and neither should be Hume’s system. Adam Smith described Hume’s death as the way an atheist should accept death with a serene, tranquil temper. But, as Zubia relates, there is another tradition about Hume’s death, whose origins are traceable to Hume’s housekeeper. Hume faced death depressed and with a gloomy temper, and convulsed with regret and worry. This tradition is the tip of a huge iceberg. Perhaps it is more difficult to live as an Epicurean as Hume lets on. Perhaps the vision of human significance and dignity—present in concern about death—should be a cause for wonder, not merely an accepted fact. Perhaps philosophy is more about preparing to die than it is about getting people to accept their chains.

Zubia’s scholarly book refuses to be merely academic. Showing the glories of the enduring Great Tradition, he provides grist of reflection and an antidote to dogmatism by showing how the issue of natural right always lurks below the surface.