 We shall not go too deeply into the matter of Bohr’s interpretation of quantum mechanics since we are mostly interested in Bohr’s view on the uncertainty principle. For a more detailed discussion of the former we refer to Scheibe (1973), Folse (1985), Honner (1987) and Murdoch (1987). It may be useful, however, to sketch some of the main points.  Central in Bohr’s considerations is the language we use in physics. No matter how abstract and subtle the concepts of modern physics may be, they are essentially an extension of our ordinary language and a means to communicate the results of our experiments.  These results, obtained under well-defined experimental circumstances, are what Bohr calls the “phenomena”. A phenomenon is “the comprehension of the effects observed under given experimental conditions” (Bohr 1939: 24), it is the resultant of a physical object, a measuring apparatus and the interaction between them in a concrete experimental situation. The essential difference between classical and quantum physics is that in quantum physics the interaction between the object and the apparatus cannot be made arbitrarily small; the interaction must at least comprise one quantum.  This is expressed by Bohr’s quantum postulate: