How are core social phenomena to be understood as modes of being? This book offers an alternative approach to social ontology. Recent interest in social ontology on the part of mainstream philosophy and the social sciences presupposes from the outset that the human being can be cast as a conscious subject whose intentionality can be collective. By contrast, the present study insistently poses the crucial question of who the human being is and how they sociate as whos. Such whoness is a clean-cut departure from the venerable tradition of questioning whatness (quidditas, essence) in philosophical thinking. Casting human being hermeneutically as whoness opens up new insights into how human beings sociate in interplays of mutual estimation that are simultaneously social power plays. Hitherto, the ontology of social power in all its various guises, has only ever been implicit. This book makes it explicit. The kind of social power prevalent in capitalist societies is that of the reified value embodied in commodities, money, capital, &c. Reified value itself is constituted through an interplay of mutual estimation among things that reflects back on the power interplay among whos. In this way a new critique of capitalism becomes possible.