Context: Humberto Maturana’s biology of cognition (BoC) represents a novel analysis of cognition grounded in biology and neuroscience. While BoC has facilitated demonstrable improvements in research and development results, it contrasts with prevailing mainstream viewpoints, models, and terminology. Accordingly, effort is required to develop a working knowledge of Maturana’s work before one can reasonably apply it or contribute to BoC’s ongoing conceptual advancement. Problem: The effort required in learning BoC increases the risk of misrepresenting or misinterpreting BoC and overlooking its value. Applying BoC requires both a working knowledge and creative adaptations. These adaptations can prove difficult and obscure recognition of credit due BoC for positive outcomes. Finally, the BoC community of interest faces challenges in absorbing lessons learned and refining the BoC conceptual framework to facilitate future researchers in benefiting from Maturana’s legacy. These issues reflect three areas of concern: (a) effectively understanding BoC; (b) usefully applying BoC; and (c) elaborating and extending BoC. Method: I identify key issues underlying these areas of concern, review lessons learned regarding the understanding and application areas, and offer recommendations for elucidating some of the most important issues for constructively advancing BoC. Using examples from successful professional experience, I illustrate the issues involved in applying BoC in research and development projects, the benefits obtained, and the problems in assigning credit for such benefits to BoC. Results: Access to fundamental BoC resources has improved over the last three decades. The specific points of difficulty in developing a working knowledge of BoC remain much the same as they were for Maturana’s university students decades ago. The four issues I consider most important for clarification or conceptual development are: A - the role and scope of autopoiesis, B - ontological and epistemological entailments of BoC, C - the entitative bias, and D - the new orientation that shifts from entities to relations. Implications: The core of biology of cognition risks increasing obscurity unless (a) its tenets are more clearly established and widely disseminated and (b) the means for applying its insights for practical benefit are developed and tested via experience. These results are offered to aid in progressing Maturana’s version of constructivism toward increased recognition of the potential value BoC - and constructivism in general - offers. Constructivist content: Maturana’s work entails a focus on an observer’s subjective experience of its life world, and therefore entails an epistemology consistent with the constructivist perspective. Key words: Applied constructivism, autopoiesis, biology of cognition, epistemology, languaging, Maturana, observer, ontology, Varela.