ABSTRACT
Both the Gor'kov and the Anderson theories contain something corresponding to a phase, and these theories started me thinking about phases in superconductors. This chapter attempts at that time to understand the structure of the superconducting state and the nature of its long-range order in terms of the kind of correlation functions that appeared in the Gor'kov theory. It focuses on the theories of superconductivity. The chapter examines the two-superconductor case and had found terms equivalent to those it had found later, but could not understand their significance and had decided that they probably had no effect. Anderson's suggestion was that only the flux in the insulating region would be effective, but using the Ginzburg-Landau theory to calculate the effects of the field the author convinced himself that the flux penetrating into the superconducting regions also contributed, and this implied that the earth's field could be important.
