During the last 15 years, cognitive scientists have discovered things about the nature and importance of metaphor that are startling because of their radical implications for metaphor research and because they require us to rethink some of our most fundamental received notions of meaning, concepts, and reason. Many of the theoretical assumptions that guided earlier generations who worked on metaphor have been undermined by this new research, which has profound implications for philosophy. More specifically, the level of methodological sophistication of empirical studies of metaphor has increased markedly, making possible rigorous, detailed analyses of how metaphors actually structure conceptualization and reasoning. In addition, professionals have learned that metaphor is not merely a linguistic phenomenon but more fundamentally a conceptual and experiential process that structures the world. The articles in this special issue make significant contributions to these advances.