Part I focuses on Spinoza's epistemology. Philosophical understanding empowers us by giving us access to truths about ourselves and the world, and by motivating us to act on them. It gives us reasons for living together and enhances our ability to live co-operatively. Part II takes up Spinoza's claim that, to cultivate this kind of understanding, we need to live together in political communities. It explores his analysis of how states can develop a co-operative ethos. Finally, living joyfully compels us to look beyond the state to our relationship with the rest of nature. James concludes with discussions of some of the virtues this requires.