Summary The question underlying this article is whether the Kantian transcendental philosophy is wide enough to constitute the objects of quantum physics as objects of possible experience and consequently to found the objectivity of quantum physical knowledge. It is shown that the Kantian determinations of the categories (quality, substance, causality) can be interpreted and elaborated in such a way that the quantum physical concept of an object characterized by nonobjectivity of properties is conceived. Therefore the categories are valid in quantum (...) mechanics and warrant the objectivity of quantum physical experience. By the interpretation of the Kantian infinite judgement as an indefinite proposition it is possible to define the non-objectivity of properties categorially as indefiniteness of qualities. In particular by the indefiniteness of the position-quality the non-permanent localizability of quantum mechanical objects can be understood a priori. However the object of possible experience, especially the quantum mechanical object is underdetermined by the categories of substance and causality: If the object is determined to be a substance it is not yet conceived to be an individual; its characterization by means of probability laws is categorially indeterminate. In so far the significance of transcendental philosophy for the foundation of quantum physics is limited. (shrink)

In this report on the present state of the discussion about the interpretation of quantum mechanics an attempt is made to provide an idea of the philosophical relevance of the foundations of physics. A simplified model of the measuring process is given which shows the difficulties in the interpretation of quantum mechanics. It is argued against Bohr's solution (also in a version of H. Putnam). Two examples show possible philosophical consequences of quantum mechanics: The variety of quantum logics challenges the (...) foundations of logic, the paradox of Einstein, Podolsky and Rosen (with Bell's inequality) may be interpreted along the lines of holism. Against alleged refutations of realism by means of quantum mechanics, a realist standpoint is maintained. A proper interpretation of quantum mechanics from an epistemological point of view seems still to be lacking. In my childhood the legend was current, that only twelve men in the World understood Einstein's theory. Nowadays, relativity is quite tame; but I shall argue presently thatnobody yet understands the quantum theory. Howard Stein. (shrink)

The author investigates which methods of naming objects are possible in the language of physics on the basis of the real physical conditions and to which extend objects thereby can be identified. It is shown that in the language of classical physics naming by designation is always possible. But this implies only the temporal identity of objects, not the "trans - world" - identity, which is important for modalities. In the language of quantum physics naming by designation is no longer (...) applicable to individuals but only to classes of equivalent objects. And for these classes temporal identity as well as the "trans - world" - identity can be produced, which means that an adequate semantics can be specified for the concept of possibility necessary in this language. (shrink)