Machines are often employed in Heidegger's philosophy as instances to illustrate specific features of modern technology. But what is it about machines that allows them to fulfill this role? This essay argues there is a unique ontological force to the machine that can be understood when looking at distinctions between techne and mechane in ancient Greek sources and applying these distinctions to a reading of Heidegger's early thought on equipment and later thought on ">poiesis. Especially with respect to Heidegger's appropriation of Aristotle's conception of dunamis (capacity, power, force, potential), it becomes apparent from a Heideggerian perspective that machines provide an increase in capacity to its human users, but only so at a cost. This cost involves a problem of knowledge where the set of operations required in machine use results in the loss of understanding our dependency on being. The essay then concludes with a discussion of how this relation to machinic capacity is not merely pessimistic and deterministic, but indicates what might constitute a free relation to machines.