It is the story of Joseph Priestley - scientist and theologian, protege of Benjamin Franklin, friend of Thomas Jefferson - an 18th-century radical thinker who played pivotal roles in the invention of ecosystem science, the discovery of oxygen, the founding of the Unitarian Church, and the intellectual development of the United States. And it is a story that only Steven Johnson, acclaimed juggler of disciplines and provocative ideas, can do justice to.

In the 1780s, Priestley had established himself in his native England as a brilliant scientist, a prominent minister, and an outspoken advocate of the American Revolution, who had sustained long correspondences with Franklin, Jefferson, and John Adams. Ultimately, his radicalism made his life politically uncomfortable, and he fled to the nascent United States. Here, he was able to build conceptual bridges linking the scientific, political, and religious impulses that governed his life. And through his close relationships with the Founding Fathers - Jefferson credited Priestley as the man who prevented him from abandoning Christianity - he exerted profound if little-known influence on the shape and course of our history.