 Since Modest Physical CTT is restricted by epistemologically relevant criteria, it doesn’t raise the worries associated with Bold Physical CTT—namely, that it’s too easy to falsify and irrelevant to the notion of computability that motivates CTT. And there are good reasons to believe Modest Physical CTT. All computing mechanisms that have been physically built or are in the process of being built to compute functions of a denumerable domain compute only functions that are Turing-computable.