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The perspective that encompasses the areas of your life that you need to maintain.
A role you play or a continuing obligation you have to yourself or others that needs to be maintained.
The perspective that focuses on your current commitments (projects).
The perspective that encompasses your 1 to 2 year goals.
GTD is a "bottom up" approach that focuses on mastering the mundane. Once that is done, though, there are higher perspectives that can really make the system bring about great results.