Open Compositionality: Towards a New Methodology of Language argues that natural languages, like English and Spanish, are not only systems of representation useful for communication but also, and most importantly, highly interactive cognitive capacities allowing humans to engage in complex forms of cognition. This view goes against the orthodoxy in philosophy of language, which considers natural languages to be specialized systems consisting of only linguistic elements and functioning in a closed compositional manner, allowing for a fully formal, algebraic descriptions. Eduardo Garcia Ramirez rejects the longstanding principle of compositionality, according to which the meaning of any complex expression is fully determined by its parts and the way they are combined, and substitutes it with an alternative, open and interactive one. This novel view of the nature of language better accounts for the empirical evidence. Garcia Ramirez develops an account of open compositionality, accompanied by the cognition first methodology, in which natural languages are conceived as supermodular cognitive capacities that allow for interaction among multiple distinct areas of human cognition. The explanatory success of this novel proposal and its accompanying methodology are tested by the author’s account of three enduring philosophical problems: substitution failure, empty names, and the nature of moral discourse.