In a clock, account is taken of some definite constellation in the world-system. When we look at the clock, we tacitly make use of the 'sun's position', in accordance with which the measurement of time gets regulated in the official astronomical manner. When we make use of the clock-equipment, which is proximally and inconspicuously ready-to-hand, the environing Nature is ready-to-hand along with it. Our concernful absorption in whatever work-world lies closest to us, has a function of discovering ; and it is essential to this function that, depending upon the way in which we are absorbed, those entities within-the-world which are brought along [beigebrachte] in the work and with it (that is to say, in the assignments or references which are constitutive for it) remain discoverable in varying degrees of explicitness and with a varying circumspective penetration.
The kind of Being which belongs to these entities is readiness-to-hand. But this characteristic is not to be understood as merely a way of taking them, as if we were talking such 'aspects' into the 'entities' which we proximally encounter, or as if some world-stuff which is proximally present-at-hand in itself1 were 'given subjective colouring' in this way. Such an Interpretation would overlook the fact that in this case these entities would have to be understood and discovered beforehand as something purely present-at-hand, and must have priority and take the lead in the sequence of those dealings with the 'world' in which something is discovered and made one's own. But this already runs counter to the ontological meaning of cognition, which we have exhibited as a founded mode of Being-in-the-world.2 To lay bare what is just present-at-hand and no more, cognition must first penetrate beyond what is ready-to-hand in our concern. Readiness-to-hand is the way in which entities as they are 'in themselves' are defined ontologico-categorially. Yet only by reason of something present-at-hand, 'is there' anything ready-to-hand. Does it follow, however, granting this thesis for the nonce, that readiness-to-hand is ontologically founded upon presence-at-hand?
But even if, as our ontological Interpretation proceeds further,  readiness-to-hand should prove itself to be the kind of Being characteristic of those entities which are proximally discovered within-the-world, and even if its primordiality as compared with pure presence-at-hand can be demonstrated, have all these explications been of the slightest help towards understanding the phenomenon of the world ontologically ? In Interpreting these entities within-the-world, however, we have always 'presupposed' the world.
1 '... ein zünächst an sich vorhandener Weltstoff ...' The earlier editions have '... zunächst ein an sich vorhandener Weltstoff ...'.
2 Sec H. 61 above.