itself? Moreover, even that which is ready-to-hand can be made a theme for scientific investigation and determination, for instance when one studies someone's environment—his milieu—in the context of a historiological biography. The context of equipment that is ready-to-hand in an everyday manner, its historical emergence and utilization, and its factical role in Dasein—all these are objects for the science of economics. The ready-to-hand can become the 'Object' of a science without having to lose its character as equipment. A modification of our understanding of Being does not seem to be necessarily constitutive for the genesis of the theoretical attitude 'towards Things'. Certainly not, if this "modification" is to imply a change in the kind of Being which, in understanding the entity before us, we understand it to possess.
In our first description of the genesis of the theoretical attitude out of circumspection, we have made basic a way of theoretically grasping entities within-the-world—physical Nature—in which the modification of our understanding of Being is tantamount to a change-over. In the 'physical' assertion that 'the hammer is heavy' we overlook not only the tool-character of the entity we encounter, but also something that belongs to any ready-to-hand equipment : its place. Its place becomes a matter of indifference. This does not mean that what is present-at-hand loses its 'location' altogether.  But its place becomes a spatio-temporal position, a 'world-point', which is in no way distinguished from any other. This implies not only that the multiplicity of places of equipment ready-to-hand within the confines of the environment becomes modified to a pure multiplicity of positions, but that the entities of the environment are altogether released from such confinement [entschrankt]. The aggregate of the present-at-hand becomes the theme.
In the case before us, the releasing from such environmental confinement belongs to the way one's understanding of Being has been modified; and it becomes at the same time a delimitation of the 'realm' of the present-at-hand, if one now takes as one's guiding clue the understanding of Being in the sense of presence-at-hand. The more appropriately the Being of the entities to be explored is understood under the guidance of an understanding of Being, and the more the totality of entities has been Articulated in its basic attributes as a possible area of subject-matter for a science, all the more secure will be the perspective for one's methodical inquiry.
The classical example for the historical development of a science and even for its ontological genesis, is the rise of mathematical physics. What is decisive for its development does not lie in its rather high esteem for the observation of 'facts', nor in its 'application' of mathematics in determining the character of natural processes ; it lies rather in the way in which Nature