Is there anything new left to say about the Declaration of Independence? This foundational American document—drafted by Thomas Jefferson and ratified by delegates from the 13 Colonies on July 4, 1776—is the impetus for all the barbecues and fireworks of the upcoming holiday as well as the subject of innumerable history lessons and memorization exercises. Historians have closely analyzed the document’s approximately 1,320 words, often celebrating them as a pure expression of American ideals and more recently observing the contradictions of a slaveholding society that advocated human freedom while withholding it from Black people.

Few phrases in the Declaration are better known than the one that furnishes the title of Peter Moore’s Life, Liberty, and the Pursuit of Happiness: Britain and the American Dream (Farrar, Straus and Giroux, June 27). “Over the past quarter millennium this felicitous line has become world famous,” Moore writes. “There is a winning clarity here. So much is evoked with such little language. In a phrase of just seven words Jefferson, it seems, has captured the unique purpose and energy of the American Revolution.”

But, as Moore demonstrates in this highly readable book, the line has a “captivating pre-history” as well; he links it to ideas expressed by British thinkers Samuel Johnson, Catharine Macaulay, John Locke, and William Strahan earlier in the 18^th century. In particular, the friendship between Strahan, a London-based printer, and Benjamin Franklin plays a crucial role in the dissemination of the Enlightenment ideas that became a cornerstone of the American Revolution. Or, as Moore succinctly puts it, “Britain first dreamed the Enlightenment dream, but it was America that made it happen.”

What, though, was the Enlightenment? In her nimble new intellectual history, Sarah Bakewell offers some definitions. “The new Enlighteners saw themselves as hoping to bring people into the light,” she explains in Humanly Possible: Seven Hundred Years of Humanist Freethinking, Inquiry, and Hope (Penguin Press, March 28). “They hoped, by means of better reasoning, more effective science and technology, and more beneficial political systems, to help their fellow humans to emerge into the sun and air and live more bravely and happily.”

Bakewell explores the ideas of numerous Enlightenment figures, including French thinkers Voltaire and Denis Diderot, Scottish philosopher David Hume, and Anglo-American pamphleteer Thomas Paine, who plays a prominent part in Moore’s book as well. Paine’s Common Sense, a fiery case for American independence published anonymously in 1775, was surely an influence on Jefferson in drafting the Declaration of Independence.

But Humanly Possible, as its subtitle suggests, widens the focus to introduce the people—from Erasmus and Petrarch in the 14^th century to Bertrand Russell and Zora Neale Hurston in the 20^th—whose work formed what Bakewell calls a “shared humanist tradition,” even if not all of them would have used the term humanist and some, in fact, predated it. Along with Moore’s book, it would make for excellent Fourth of July reading as we contemplate the theoretical underpinnings—along with the practical successes and failures—of the American democratic experiment.

Tom Beer is the editor-in-chief.