Hope is itself a species of happiness, and, perhaps, the chief happiness which this world affords: but, like all other pleasures immoderately enjoyed, the excesses of hope must be expiated by pain; . . .
Source: Letter, 8 June 1762 (published in Boswell, Life of Samuel Johnson, 1791).
-- Samuel Johnson, (Sep 18 1709-1784), English lexicographer, critic; He was remembered for writing the first critique of Shakespeare, 1765 and Dictionary of the English Language, 1755.