  Heidegger, then, denies that the categories of subject and object characterize our most basic way of encountering entities. He maintains, however, that they apply to a derivative kind of encounter. When Dasein engages in, for example, the practices of natural science, when sensing takes place purely in the service of reflective or philosophical contemplation, or when philosophers claim to have identified certain context-free metaphysical building blocks of the universe (e.g., points of pure extension, monads), the entities under study are phenomenologically removed from the settings of everyday equipmental practice and are thereby revealed as fully fledged independent objects, that is, as the bearers of certain context-general determinate or measurable properties (size in metres, weight in kilos etc.). Heidegger calls this mode of Being presence-at-hand, and he sometimes refers to present-at-hand entities as ‘Things’. With this phenomenological transformation in the mode of Being of entities comes a corresponding transformation in the mode of Being of Dasein. Dasein becomes a subject, one whose project is to explain and predict the behaviour of an independent, objective universe. Encounters with the present-at-hand are thus fundamentally subject-object in structure.