This chapter establishes a new interpretation of Spinoza’s political conception of potentia, from within his broader metaphysical framework. Centrally, the chapter distinguishes between, on the one hand, potentia operandi (power of producing effects, for better or for worse, with no particular connection to virtue), which is similar to Hobbes’s notion of power; and, on the other hand, potentia agendi (power of acting), associated with a thing’s essence and virtue. An entity may be extremely powerful in the first sense without being powerful in the second sense. Politically, this manifests as a distinction between merely having right and power, versus being in control of one’s own right (being sui juris). Sui juris status is normatively desirable, but in this chapter the relation (and possible divergence) between the sui juris status of a political collectivity and the sui juris status of the members making up that collectivity is not yet established.