Book excerpt: Simo Knuuttila was an influential philosopher, theologian, and historian of philosophy who conducted research on a variety of topics including modalities, emotions, perception, and change in different historical periods, from Ancient to Modern. His contribution to the study of modalities and emotions was groundbreaking and trendsetting with a lasting impact on the area. In this volume, a group of international scholars – all of whom worked directly with Knuuttila – elaborate on some of those topics, trying to understand the core interpretative ideas, the polemical aspects, and how to develop those interpretations in different authors and/or conceptual frameworks. The result is an unique volume that presents a broad range of perspectives on key topics in the history of philosophy in the last decades, both influenced and challenging the interpretations advocated by Knuuttila.