Why have highly abstract ideas such as truth, knowledge, or justice become so profoundly important to us? What is the purpose of thinking in these terms? In this remarkable book, "The Practical Origins of Ideas," Matthew Kilo—winner of the 2020 Loewer Award for Emerging Philosophers—presents a philosophical approach to answering such questions: the method of pragmatic genealogy.

Pragmatic genealogy is partly fictional narratives and partly historical accounts, exploring what might drive us to develop certain ideas in order to understand how we benefit from them. This book reveals an underexplored tradition of pragmatic genealogy that intersects with the analytic and continental divide in philosophy: from David Hume's state of nature scenarios and Friedrich Nietzsche's early genealogies, to contemporary works in analytic philosophy by Edward Craig, Bernard Williams, and Miranda Fricker. However, these genealogies combine fiction and history in ways that even philosophers sympathetic to the use of state-of-nature narratives or real history have found puzzling. To understand why both fiction and history are needed, the book provides a systematic framework for pragmatic genealogies as dynamic models that reverse-engineer ideas, not only in terms of quasi-universal human needs, but also historical social needs. This allows the method to offer us an unreduced explanation and helps us understand what guided our ideas to the effects of their practical origins. Furthermore, far from being normatively neutral, pragmatic genealogy can influence the scope of reasons, which in turn can guide our attempts to develop our conceptual repertoire by helping us determine whether and when our ideas are worth holding.