I conclude by summarising the direct and indirect arguments offered in support of Heidegger’s claims that human mindedness and agency are intrinsically embedded within a shared world and that the shared world constitutes the most basic form of intersubjectivity.

The introduction presents some general reflections on what characterises Heidegger’s fundamental ontology and what makes his thought a particularly promising point of departure for doing social ontology. I first introduce Heidegger’s holistic conceptions of Dasein and being-in-the-world by way of contrast to Cartesian atomism. I then go on to show that Heidegger conceives of intersubjectivity as a triangular relation between self, world, and other rather than a dyadic relation between two independent subjects. My claim is that Heidegger’s social ontology is found directly in his conception of the shared world and that his more well-known accounts of the Anyone and solicitude should be understood within this general framework. I also reflect on the relation between Heidegger’s social ontology and his politics and provide an outline of the book.