 Thus when, a few pages later, Turing asserts that “machine processes and rule of thumb processes are synonymous” (1947: 383), he is to be understood as advancing the Church-Turing thesis (and its converse), not a version of the maximality thesis. Unless his intended usage is borne in mind, misunderstanding is likely to ensue. Especially liable to mislead are statements like the following, which a casual reader might easily mistake for a formulation of the maximality thesis: 