 For still different approaches to the second incompleteness theorem, see Feferman 1982, 1989a; Visser 2011. For some philosophical complications concerning the second theorem, see Detlefsen 1979, 1986, 1990, 2001; Auerbach 1985, 1992; Roeper 2003; Franks 2009 (see also section on incompleteness in the entry on  Hilbert’s program).