This chapter focuses on the major works of Baruch Spinoza as they impact upon politics, particularly the posthumously published Ethics (1677). This broadly philosophical work, composed over fifteen years, opens up many important ideas that are further developed in Spinoza’s two explicitly political works, Theologico-Political Treatise (1670) and the unfinished Political Treatise. The chapter explores some of the key ideas and concepts to be found in Ethics, including the concepts of nature, individuality, mind and body, imagination, and freedom. It then deepens the political ground of these concepts by addressing power and democracy. The chapter also advances Spinoza’s idea of the multitude and considers some of the political exclusions present in his political philosophy. While one may find limits in the perception of political equality, gender, and race in his works, Spinoza’s analysis of the relationship between the human condition and the natural world remains deeply prescient for many radical political thinkers reflecting on such themes today.