On the day C.S. Lewis died, his last written work was already in press with the Saturday Evening Post. “We have no ‘right to happiness,’” Lewis declared in the essay, by which he meant that we have no moral right to trample the rules of justice to gratify our impulses.

Lewis did concede that the idea of a right to the pursuit of happiness is “cherished by all civilized men, but especially by Americans.” However, the authors of the American Declaration of Independence, according to Lewis, could only have meant that we have a right “‘to pursue happiness by all lawful means’: that is, by all means which the Law of Nature eternally sanctions and which the laws of the nation shall sanction.”

In her new book The Pursuit of Happiness in the Founding Era: An Intellectual History, Carli Conklin has assembled a wealth of evidence that supports Lewis’s basic insight.

Far from being a “glittering generality” or a euphemism for property, the “pursuit of happiness” had a distinct and widely understood meaning in the eighteenth century. It “refers to man’s ability to know the law of nature as it pertains to man,” Conklin concludes, “and man’s unalienable right to then choose to pursue a life of virtue or, in other words, a life lived in harmony with those natural law principles.”

This broadly Aristotelian understanding of the pursuit of happiness cut across the eclectic intellectual traditions that informed the American founding, including the classical Greek and Roman traditions, Christianity, the English common law, and Newtonian science.

It is telling, Conklin notes, that, throughout the drafting of the Declaration of Independence, and despite the numerous changes great and small that were made to the document, no one ever disputed the initial inclusion of “the pursuit of happiness” as an inalienable right alongside the rights of life and liberty. “The lack of editing here,” Conklin concludes,

would suggest one of two things: either the phrase “pursuit of happiness” really was a glittering generality with a non-substantive meaning to which no one would object, or it had a substantive meaning that was both understood by and agreeable to the wide variety of individuals involved in drafting and editing the Declaration.

Like Lewis, Conklin thinks the writers of that declaration meant that we have a right to pursue happiness by all lawful means, which are the only means by which we can attain happiness in the first place. Perhaps this is a tautology—we have a moral right to do only what is morally right—but it is nonetheless important for what it affirms (the reality of the natural law) and for what it denies (any right to pursue happiness independent of the natural law).

The shared background assumptions that made sense of the inalienable right to the “pursuit of happiness” in the Founding era included a belief that God created the universe and the natural laws that direct the universe to its ultimate end or perfection. These laws include the physical laws that govern the inanimate and non-rational parts of creation, but also the moral law of human nature. The latter clarifies what constitutes genuine human well-being and thereby helps man to pursue his own happiness, or flourishing, by living a life of virtue.

The eighteenth-century English jurist William Blackstone even went so far as to reduce the natural law to “God’s one paternal precept: ‘that man should pursue his own true and substantial happiness’” (as opposed to that fleeting and temporal happiness that is unmoored from virtue). James Wilson—one of only six men to sign both the Declaration of Independence and the US Constitution—later echoed Blackstone when he summarized the natural law with “this one paternal command: Let man pursue his own happiness and perfection.”

All of this is hiding in plain sight. In his Commentaries on the Laws of England, Blackstone wrote that “when the supreme being formed the universe, and created matter out of nothing, he impressed certain principles upon that matter, from which it can never depart, and without which it would cease to be.” He then went on to draw an analogy between the laws of physical nature and the moral law of human nature, writing that,

God, when he created matter, and endowed it with a principle of mobility, established certain rules for the perpetual direction of that motion; so, when he created man, and endowed him with free will to conduct himself in all parts of life, he laid down certain immutable laws of human nature, whereby that free will is in some degree regulated and restrained, and gave him also the faculty of reason to discover the purport of those laws.

As Conklin notes, Blackstone was clear “that the immutable laws of nature that pertain to the physical world (inanimate or animate, irrational creation) and the immutable law of nature that pertains to man (animate, rational creation) are put in place by a Creator God to govern all creation.”

This same framework and distinction are preserved in the Declaration of Independence, even in Jefferson’s original rough draft that declared the “sacred and undeniable” truth that “all men are created equal” and that “from that equal creation” men derive “inalienable” natural rights. The final document, after extensive drafting and editing, appeals to the “Laws of Nature and of Nature’s God” and clearly identifies that God as the “Creator” of nature and the “Supreme Judge of the world,” who governs his creation through an overarching “Divine Providence.”

The pursuit of happiness is embedded in the Declaration in a larger theological context, just as it is in Blackstone’s Commentaries. Admittedly, Jefferson was not an admirer of Blackstone (he called him a “honeyed Tory”), but Conklin makes a convincing argument that Jefferson tracked Blackstone closely in his treatment of the pursuit of happiness.

Yes, Jefferson and some of the principal Founders―including the other members of the Committee of Five that wrote the Declaration, especially Benjamin Franklin and John Adams—held unorthodox religious beliefs. Nonetheless, all of these men publicly and privately affirmed a shared natural theology: that there is a Creator who has imbued the world with discernible natural laws, both physical and moral, and who governs the affairs of men with his sustaining and intervening providence.

Michael Pakaluk, following Avery Cardinal Dulles, refers to this natural theology as the “deist minimum” that in late eighteenth-century America was combined with providentialism and was “held by Christians of all denominations (and also by Jews and philosophical theists), who nonetheless might differ on what additional doctrines were revealed.”

This combination of the deist minimum with providentialism served as a workable and stable public theology that made sense of the Declaration’s right to the pursuit of happiness: the latter is coherent only against this backdrop. The right was understood to be bounded by a God-given natural law that was affirmed by each of the various intellectual traditions that underpinned the American Founding.

If Conklin is right about all of this, then we must consider the possibility that Lewis was right as well: that the privileging of individual will over and against the natural moral law is the outgrowth not of the acceptance of the inalienable right to the pursuit of happiness, rightly understood, but rather of its repudiation.

Justin Dyer is professor of political science and director of the Kinder Institute on Constitutional Democracy at the University of Missouri. Republished with permission from The Public Discourse.