Memoirs of Margaret Fuller Ossoli
p211“I have just been reading Goethe's Lebensregel.”
Emerson, Ralph Waldo, William Henry Channing, and James Freeman Clarke, eds. Memoirs of Margaret Fuller Ossoli. 2 vols. Boston: Phillips, Sampson and Company, 1852.
The editors identify this as Goethe's poetic rule of life, found within his collected works.