Abstract

We argue that Bohrian complementarity is a framework for making new ontological sense of scientific findings. It provides a conceptual pattern for making sense of the results of an empirical investigation into new realms or fields of natural properties. The idea of “formation length” engenders this mutual attunement of evidence and reality. Physicists want to be able to ascribe ontological features to atomic constituents and atomic processes such as “emission”, “impact”, or “change of energy-state”. These expressions supposedly refer to “local” forms of physical change that in sum constitute the possibility of there being a “global” (for example an atomic) system of possible states. We argue that it is only because we can act it out in the design of experiments that we canmake sense of the link between classical and quantum theoretical systems. We need the notion of formation length in order to express the principle that the atom is a causal unity. This not in the sense of being the ground for a particular kind of causality, but in the sense of unifying the grounds for the variety of causal manifestations that constitutes the atom.