 A promising place to start is the modal status of God’s existence. In Ip11, Spinoza claims that God necessarily exists. But what is it in virtue of which God necessarily exists? This might sound like an odd question. Once explanations reach a necessarily existing object, are there further in virtue of questions to be asked about that object’s existence? More generally, when we reach necessity, haven’t we  reached the end of   explanations?[14] Not always: mathematics is full of asymmetrical dependence relations among necessarily true propositions. Similarly, Spinoza thinks that substance causes and asymmetrically explains necessarily existing infinite modes. Hence Spinoza must believe that dependence and explanation are more fine-grained relations than modern logical entailment, since according to the latter, every necessary proposition entails and is entailed by every other necessary proposition.