Summer on the Lakes, in 1843
“We get the better because we do "Look before and after." But, from the same cause, we "Pine for what is not.”
Fuller, Margaret. Summer on the Lakes, in 1843. Boston: Little, Brown & Co., 1844.
Inferred The exact phrase 'pine for what is not' is from Shelley's 'To a Skylark' (1820), stanza 18: 'We look before and after, / And pine for what is not: / Our sincerest laughter / With some pain is fraught; / Our sweetest songs are those that tell of saddest thought.'