 The most celebrated of the theorems Gold proved (using some reasoning remarkably similar to that of Putnam 1963) showed that a language learner could be similarly hostage to malign environments. Imagine a learner being exposed to an endless and ultimately exhaustive sequence of presented expressions from some target language—Gold calls such a sequence a ‘text’. Suppose the learner does not know in advance whether the language is infinite, or is one of the infinitely many finite languages over the vocabulary V. Gold reasons roughly thus: