The paper aims to contribute to macroeconomic and methodological discourse on the concept of a green economy from the perspective of sustainable development. The authors hypothesize that the legitimacy and cognitive effectiveness (“heuristic fertility”) of the green economy concept and the effective implementation of its principles are closely related to intersubjective methodological discourse in this area. In their research, the authors use recent methodology advances, referring to various constructivist approaches and providing a critical analysis of the so-called correspondence approach. The article juxtaposes the macroeconomic context of research into the green economy and the knowledge-based economy (KBE) with the theory of sustainable development. The authors propose a wider approach to the KBE, taking into account axiological aspects and cultural processes accompanying the creation of knowledge and making the green economy take different forms in various countries. The authors argue that a knowledge-based economy is an open, complex and dynamic subsystem in which qualitative changes are triggered by the wisdom of units capable of promoting more efficient and better solutions through a broader cognitive perspective. Such a definition of KBE implies the need to discover and understand various subtle links between the economy and other subsystems: environmental and social. Economic activity needs to be adapted to the potential of these subsystems, which is particularly important from the perspective of the green economy. This creates a situation in which the rational actions of individuals are not only based on simple arithmetic calculations but also refer to ethical value judgments.