This last comment suggests an element of serendipity in human affairs, one that Johnson also discusses brilliantly in another of his books, The Ghost Map. Priestley played a central and prominent role (albeit an underappreciated one since then) during the Enlightenment and the American Revolution, simultaneously. As Johnson notes on Page 147, “Scientific innovation tends to be imagined as something that exists outside the public sphere of politics, or the sacred space of faith…But for Priestly, these three domains [i.e. science, religion, and politics] were not separate compartments, but rather a kind of continuum, with new developments in each domain reinforcing and intensifying the others.” For me, those comments capture the essence of what motivated Priestly. They also help to explain the nature and extent of his appeal and influence during an era in which there was no shortage of human talent and skill.

The title of this book should not be interpreted literally. Rather, it refers to a process of rigorous scientific inquiry over time during which men such as Franklin and Priestley began to formulate (“invent”) concepts to increase human understanding of natural forces. Note Johnson’s lengthy discussion of waterspouts in the Prologue, “The Vortex.” In fact, Johnson observes, “One of Priestley’s greatest scientific discoveries involved the cycle of energy flowing through all life on Earth, the origin of the very air he was breathing there on the deck [of the ship transporting him from England to America] as he watched his thermometer line bob in the waters of the Atlantic. Together, all those forces converged on him, as the Samson struggled against the current bearing west to the New World…”

As we proceed into an uncertain future, Steven Johnson asserts, we must rely on old institutions and remain hostage to what James O’Toole characterizes as “the ideology of comfort and the tyranny of custom” because that would betray “the core and, connected values that Priestly shared with the American founders.” Today, “we now see the web of relationships far more clearly than Priestly or Franklin or Jefferson could” and thus can take full advantage of opportunities in a world “still ripe for radical change.” There is indeed cause for hope.