Shakespeare's choice of stories was clearly determined by the Elizabethan conception of tragedy and by the current tastes of the theatre. And by these stories his imagination was directed and limited. However absorbed he became in character or ethics, he never neglected the plot or the theatre. Consequently the great revelation of tragic fact which he gave to posterity was limited by these stories of crime and hampered by their improbabilities and stage effects. The tragedy of ambition is limited to the story of a murderer who sees a ghost; and the tragedy of ingratitude is joined to a relation of senile folly, crime, and the humors of Tom of Bedlam. Even his interpretation of human motives suffers, for the bloodthirstiness of Hamlet and the perverse reticence of Cordelia belong to the old plots as much as to the characters. Yet Shakespeare's greatness of mind no less than his responsiveness to contemporary taste appears in his very choice of material. Whether he took the oft-told tragedies of Cæsar, Brutus, Antony and Cleopatra, or the old plays of Hamlet and Lear, or the neglected themes of Othello and Macbeth, he chose always stories of great dramatic interest and those that presented the range and vicissitudes of human passion. His attraction for each story was evidently in the emotional conflict that made each protagonist a great acting part and also a fascinating study of human motive. Moreover, in his general treatment of this material there is a uniformity that gives some hint of a Shakespearean definition of tragedy. In each play a man of great attainments is presented as involved in a moral conflict that results in his death. This conflict is two-fold, internal between opposing desires, and external against some persons of the counter-actions. Conflicting forces contend for mastery in the hero's breast, and from their confusion he drives on to action that is disastrous. The unusual powers, the best potentialities, of his nature are opposed and thwarted by the forces of chance and circumstance beyond his control; by the force of evil, whether in his own breast or represented by the crime and intrigue of others; and still further, by a defect or deficiency in his own personality. The force of chance, equivalent to the Greek Fate, plays a part in all tragic story and drama; the power of evil without or within was the counter-force in medieval drama, and was the theme most powerfully dwelt upon by Shakespeare's immediate contemporaries. The fateful power of incompatibility of temperament with conditions of life seems to have been Shakespeare's own conception.