What does Heidegger mean by ontotheology, and why should we care? We will see that Heidegger understands ontotheology as the two-chambered heart of Western metaphysics, “the history that we are” (N3 20/GA47 28). As I showed in Heidegger on Ontotheology: Technology and the Politics of Education, Heidegger's deconstruction of the metaphysical tradition leads him to the view that metaphysics does not just concern philosophers isolated in their ivory towers; on the contrary, “Metaphysics grounds an age.” As he explains: “Metaphysics grounds an age in that, through a specific interpretation of what is …, it gives the age the ground of its essential form” (QCT 115/GA5 75). Here Heidegger advances the thesis I call ontological holism. Put simply: Everything is, so by changing our understanding of what “is-ness” itself is, metaphysics can change our understanding of everything. In other words, metaphysics molds our very sense of what it means for something – anything – to be. Because everything intelligible “is” in some sense, Heidegger holds that: “Western humanity, in all its comportment toward entities, and that means also toward itself, is in every respect sustained and guided by metaphysics” (N4 205/GA6.2 309).