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 Ree, Times Literary Supplement\"Latour\'s work makes the world-sorry, worlds-interesting again.\"-Stephen Muecke, Los Angeles Review of Books CPSIA choking or other US hazard warning -No California Proposition 65 hazard warning necessary