4 It is worth remarking that the classical predicate calculus is translatable into intuitionist logic in a constructive way that preserves deducibility (see Bell and Machover, 1977). This means that all the theorems of classical mathematics expressible in the predicate calculus can be represented as intuitionistic theorems. Thus classical mathematics cannot easily be claimed to be intuitionistically unintelligible. (Note that the reverse translation procedure is intuitionistically unacceptable, since it replaces ‘-P’ by ‘P’, and’ -(x)-P ‘(Ex)P’ reading-,(x), and (Ex) as ‘not’, ‘for all x’ and ‘there exists x’ , respectively).