Envy is a vicious and shameful response to the good fortune of others, one that ruins friendships and plagues societies-or so the common thinking goes, shaped by millennia of religious and cultural condemnation. Envy's bad reputation is not completely unwarranted; envy can indeed motivate malicious and counterproductive behavior and may strain or even tear apart relations between people. However, that is not always the case. Investigating the complex nature of this emotion reveals that it plays important functions in social hierarchies and it can motivate one to self-improve and even to achieve moral virtue. Philosophers and psychologists in this volume explore envy's characteristics in different cultures, spanning from small hunter-gatherer communities to large industrialized countries, and contexts as diverse as academia, marketing, artificial intelligence, and Buddhism. They explore envy's role in both the personal and the political sphere, showing the many ways in which envy can either contribute or detract to our flourishing as individuals and as citizens of modern democracies.