 CT might be formulated in terms of λ-definability or Turing computability or a number of other distinct mathematical conditions known to be extensionally equivalent to recursiveness. Despite these equivalences, the differences are significant. On several occasions, Gödel expressed a strong preference for Turing’s analysis and there are good reasons for Gödel’s preference. These are amply detailed elsewhere (see the entry on the  Church-Turing thesis  as well as Davis 1965). Church himself thought that Turing’s analysis was superior to his: