The final reason that I have identified for the growing recognition of GTD is one that I doubt I can explain in nice, concise terms, for it involves the more subtle arenas of psychology, aesthetics, and spirituality. I don’t claim to have any significant expertise in any of these fields, but there is an aspect of GTD and its expression that seems to resonate with something deeper and more meaningful than simply the specifics of the topics and contents with which it coaches people to work. I will be bold enough to suggest that GTD approaches the world in much the same way that art, psychology, and spirituality have: as a framework to understand and experience new levels and depths of truth and reality.
— Making It All work, David Allen