Chapter One (‘A New Ancient Petrography’) provides an overview of the Ancient Greek word horos as it appears in the archaeological record and textual tradition. Given that the definition of its verbal cognate is ‘to determine, divide, define,’ it is suggested that this division is in the heart of language itself. Boundary markers must be read or interpreted as such, implying that the boundary is not a reductively material thing but is something dependent upon us, inside of us. Whatever it was that led us to create boundaries—to make distinctions—also bound us to our linguistic distinctions. This is what a materialist disposition would describe us as: the inscribers, the plinth-builders. The horos, at once stone and term, raises the problem of the boundary between nature and human, between worked stone and natural stone. This problem comes down to us in our distinctions of the physical world. In the absence of a demiurge, matter is supposed to be without meaning, and this is the basis for scientific rationalism. However, even the distinction between meaning and matter relies upon a conceptual acceptance that the boundary between the two is in some way naturally given. This chapter raises the problem of such distinctions and claims that any attempt to define humans as separate to everything else always ends up back at the coincidence of word and stone.