In this paper I offer an interpretation of the Stoic argumentum ex gradibus entium as it appears in Book II of Cicero's De Natura Deorum. In addition to displaying certain similarities to later formulations of the so-called "ontological argument," particularly Anselm's, I argue that the argument ex gradibus entium was a versatile feature of Stoic philosophical theology, capable of employment in relation to two distinct topics: the existence of god and the identification of god's essential nature with the world. I claim that the instance of the argument ex gradibus entium at ND II 18-21 is a token of this latter type, and show that there are no textual reasons precluding this interpretation. In light of the fact that the argument can be analyzed more effectively in this role, I suggest that this particular instance of the argument is best thought of as an attempt on the part of the Stoics to identify the world with god rather than as a strict proof for god's bare existence. I end with some reflections on the general type of the Stoic argument qua precursor to two of Anselm's ontological proofs. Although I think it is a mistake to call the Stoic argument "ontological" in a strict sense, it may, I suggest, have shared a similar conceptual underpinning with at least one of Anselm's famous formulations.