Essay on Poetry (published 1723). Compare: "'High characters,' cries one, and he would see/ Things that ne’er were, nor are, nor e’er will be", John Suckling, The Goblins, Epilogue. "Whoever thinks a faultless piece to see,/ Thinks what ne’er was, nor is, nor e’er shall be", Alexander Pope, An Essay on Criticism (1711), Part II, line 53.https://en.wikiquote.org/wiki/John_Sheffield%2C_1st_Duke_of_Buckingham_and_Normanby