Let's say I want to justify my work or vocation by citing virtue X. (X might be practical value, social utility, human happiness, etc.) Must my particular work effect virtue X, or is it sufficient that my line of work effect X generally, my personal lack of any contribution notwithstanding.
For example: Let's say I'm a scientist who, despite a great deal of effort, never discovers or creates or accomplishes anything useful. Could I justify my work by saying, "Science is useful"? (After all, even if science is useful generally, nothing I've done personally is useful.)
[You can imagine analogous scenarios involving any pursuit, e.g., poetry or investment banking.]