This study examines three distinct theoretical frameworks. First, following the events of May 1968, a shift occurred between first- to second-order cybernetics, during which systems thinking emerged as a transdisciplinary framework for modelling dynamic structures and processes. Second, in 1969, Gordon Pask, a pioneer of cybernetics and emerging artificial intelligence, suggested that cybernetics could serve as a metalanguage for architecture. His Conversation Theory provides an externalist lens for examining dialogue, learning, and collaborative conceptual processes. Third, in 1971, Philippe Boudon initiated Architecturology, an emerging science aimed at formalizing architectural reasoning through conceptual models, using an internalist approach. Although distinct in origin and orientation, these three frameworks converge in their focus on the modeling of conceptual processes. A direct comparison between Conversation Theory and Architecturology remains limited, as they address different phenomena: learning and understanding in Pask’s externalism, and design reasoning in Boudon’s internalism. However, by mobilizing general concepts of systems thinking as a common metalanguage, this research aims to identify convergences, divergences and potential complementarities. The method consists of a systematic conceptual analysis, positioning systems theory as a meta-framework that bridges Pask’s externalist view of interaction and Boudon’s internalist view of reasoning. Practically, the study applies a selected set of systemic concepts to both theories to assess their structural and dynamic correspondences, offering a new perspective on the formalization of theoretical models. The findings reveal previously unexplored conceptual interactions at a meta-level: despite their disciplinary distance, both theories rely on shared systemic mechanisms, demonstrating that systems thinking can function as a metatheory for modelling conceptual reasoning.