Naturalists seek to ground what exists in a set of fundamental metaphysical principles that they call ‘nature’. But metaphysical principles can’t function as fundamental explanatory grounds, since their ability to explain anything depends on the intelligibility granted by transcendental structures. What makes metaphysical principles intelligible, what unifies them, and allows them to characterize the being of worldly objects are the transcendental structures through which worldly objects are manifest. This means that the search for fundamental explanatory grounds must go deeper than (...) the postulation of brute metaphysical facts. But this search cannot end with transcendental structures either, since the mode of being of transcendental subjects also calls out for explanation. Conceiving of transcendental subjects through the concept of being-in-the-world ties the mode of being of subjects to the world they inhabit. What grounds the existence of worldly objects, and what grounds our existence as being-in-the-world is nature: a principle that is neither an object, nor a subject – a principle that makes possible our encounters with intelligible worldly things. (shrink)