Abstract
A remarkable philosophical affinity may be observed between the intuitionistic conception of mathematics and the transformational generative approach to the study of language: both disciplines profess a mentalistic ontology, both posit an idealized subject, and both insist on their autonomy with respect to other disciplines. This philosophical parallel is formalized in terms of a generalization of the intuitionistic notion of creative subject; resulting are the foundations of a unified theory of mental acts based on intuitionistic logic — capturing, inter alia, similarities between proof acts and speech acts. As an application of the theory, it is then shown how the notion of mental act may provide for an insightful formalization of various hypotheses pertaining to the linguistic dependence or relativity of mathematics.