Heidegger’s model of a knowable object is, significantly, a tool: we know the world not contemplatively, but as a system of unrelated things which, like a hammer, are ‘to hand’, elements in some practical project. Knowing is deeply related to doing. But the other side of that peasant-like practicality is a contemplative mysticism: when the hammer breaks, when we cease to take it for granted, its familiarity is stripped from it and it yields up to us its authentic being. A broken hammer is more of a hammer than an unbroken one.
— Literary Theory: An Introduction, by Terry Eagleton (p.64)