Common Sense, 11 June 1737 . The same complaint was made frequently by Johnson; e.g.
'Whatever can happen to man has happened so often, that little remains for fancy and invention' (see Boswell, Life, ii. 358, n. 3).
But already there were some who rejected this rather defeatist attitude and stressed the need for originality. See especially Edward Young, Conjectures on Original Composition, 1759.