Preface to Shakespeare
Tragedy was not in those times a poem of more general dignity or elevation than comedy; it required only a calamitous conclusion, with which the common criticism of that age was satisfied, whatever lighter pleasure it afforded in its progress.
History was a series of actions, with no other than chronological succession, independent of each other, and without any tendency to introduce or regulate the conclusion. It is not always very nicely distinguished from tragedy. There is not much nearer approach to unity of action in the tragedy of "Antony and Cleopatra", than in the history of "Richard the Second". But a history might be continued through many plays; as it had no plan, it had no limits.