Chaïm Perelman, alone, and in collaboration with Lucie Olbrechts-Tyteca, developed the New Rhetoric Project (NRP), which is in use throughout the world. Sir Brian Vickers, in his historical survey of rhetoric and philosophy for the Oxford Encyclopaedia of Rhetoric, states that the NRP is “one of the most influential modern formulations of rhetorical theory.” This book provides the first deep contextualization of the project’s origins, offers seven original translations of the writings of Perelman and Olbrechts-Tyteca from French into English, and details how their collaboration effectively addresses then philosophical problems of our age.