The Idea of a unified foundation of all reality has long been core to many attempts at a fundamental ontology, as well as many arguments for the divine. In medieval India a cluster of arguments for metaphysical inheritance, causal entanglement, the impossibility of fundamental relations and more, were advanced together to show there must be an ultimate and unified ground. But foundationalism has been under attack in both recent metaphysics, and Buddhist philosophy. This article unpacks Vedānta’s defense of divine foundationalism (...) against Madhyamaka Buddhism’s metaphysical nihilism. Firstly, we look at how inheritance arguments for ultimate ground aimed to circumvent the possibility of infinite regress. Secondly, we assess three arguments that this ground is a unified modal anchor, with entangled causal power, providing a connective medium for all phenomena. We address some caveats and limitations, but go on to argue that if they are right, they circumvent the Buddhists’ ‘dualistic’ assumption that if the empirical world is mere imagined convention, it needs no explanation. Monists and nihilists are allies against excessively realist ontologies, but these arguments make a compelling case for some unified fundamental nature from which, as the Upaniṣads put it, all things emerge like sparks from a fire. (shrink)