Over the past twenty-five years, Bruno Latour has developed a research protocol different from the actor-network theory with which his name is now associated—a research protocol that follows the different types of connectors that provide specific truth conditions. These are the connectors that prompt a climate scientist challenged by a captain of industry to appeal to the institution of science, with its army of researchers and mountains of data, rather than to “capital-S Science” as a higher authority. Such modes of extension—or modes of existence, Latour argues here—account for the many differences between law, science, politics, and other domains of knowledge. “Magnificent…An Inquiry into Modes of Existence shows that [Latour] has lost none of his astonishing fertility as a thinker, or his skill and wit as a writer…Latour’s main message—that rationality is ‘woven from more than one thread’—is intended not just for the academic seminar, but for the public square—and the public square today is global as never before.”—Jonathan Rée, Times Literary Supplement“Latour’s work makes the world—sorry, worlds—interesting again.”—Stephen Muecke, Los Angeles Review of Books