Accordingly, for classical physics every state of motion of bodies that occupy space is at any time simultaneously determinable—i.e., is precisely calculable in advance, predictable—both as to position and as to velocity. In contrast to this, in atomic physics a state of motion may on principle only be determined either as to position or as to velocity. Correspondingly, classical physics maintains that nature may be unequivocally and completely calculated in advance, whereas atomic physics admits only of the guaranteeing of an objective coherence that has a statistical character.
The objectness of material nature shows in modern atomic physics fundamental characteristics completely different from those that it shows in classical physics. The latter, classical physics, can indeed be incorporated within the former, atomic physics, but not vice versa. Nuclear physics does not permit itself to be traced back to classical physics and reduced to it. And yet—modern nuclear and field physics also still remains physics, i.e., science, i.e., theory, which entraps objects belonging to the real, in their objectness, in order to secure them in the unity of objectness. For modern physics too it is a question of making secure those elementary objects of which all other objects in its entire area consist. The representing belonging to modern physics is also bent on "being able to write one single fundamental equation from which the properties of all elementary particles, and therewith the behavior of all matter whatever, follow."*
This rough indication of a distinction between epochs within modern physics makes plain where the change from the one to the other takes place.26 in the experience and determination of the objectness wherein nature sets itself forth. Nevertheless, what does not change with this change from geometrizing-classical physics to nuclear and field physics is this : the fact that nature has in advance to set itself in place for the entrapping securing that science, as theory, accomplishes.
* Heisenberg, "Die gegenwärtigen Grundprobleme der Atomphysik." See Wandlungen in den Grundlagen der Naturwissenschaft (1948 ed.), 8 : 98.
26. For the meaning of "epoch," see T 43 n. 10.