Official museum definitions are indispensable because by having them we can have a strong, basic frame of reference to manage the institution's functions and its role in society. All usable definitions are much so that their differentiation has limited practical consequences; however, their precision helps legal and professional interpretations; their changes demonstrate their importance and illustrate the evolution of our mission and the ways we deal with it in practice.
My intention is not to propose the new definition or support any so far used. All I wish is to explain further the implications of any and contribute to the ongoing discussion. I would support the case by adding to the speculative level of definitions, as they are a constant reminder for the re-invention of institutions and inspiration for their evolving mission.
Explaining to my students the content of my historical collection of museum definitions, I started or ended lectures upon the subject with a provocatively brief and the most general one I was able to create:
A museum is any regular, intentional, transfer of collective experience aimed at the advancement of the human condition.