In Shakespeare not only is this very effective dramatic touch omitted, but Portia sends Brutus an encouraging message. As her weakness increases upon her, she collects herself for a final effort and manages to give the command:
Run, Lucius, and commend me to my lord:
Say, I am merry: come to me again
And bring me word what he doth say to thee.
(II. iv. 44.)
Shakespeare may perhaps have been unwilling to introduce anything into the assassination scene that might distract attention from the decisive business on hand, but the alteration is chiefly due to another cause. These, the last words we hear Portia utter, were no doubt intended to bring out her forgetfulness of herself and her thought of Brutus even in the climax of her physical distress.
This, of course, does not affect our general estimate of Portia; but Shakespeare has no scruple about creating an entirely new character for a minor personage, and, in the process, disregarding the hints that he found and asserting quite the reverse. Thus Plutarch has not much to say about Casca, so Shakespeare feels free to sketch him after his own fancy as rude, blunt, uncultured, with so little education that, when Cicero speaks Greek, it is Greek to him. This is a libel on his up-bringing. Plutarch in one of the few details he spares to him, mentions that, when he stabbed Caesar, “they both cried out, Caesar in Latin, ‘O vile traitor, Casca, what doest thou?’ and Casca in Greek to his brother: ‘Brother, helpe me.’”
But some of Shakespeare’s interpolations are, probably unawares to himself, of a vital and radical kind, and affect the conception of the chief characters and the whole idea of the story. Take, for example, Brutus’ soliloquy, as he rids himself of his hesitations and scruples. This, from beginning to end, is the handiwork of Shakespeare:
It must be by his death: and, for my part
I know no personal cause to spurn at him,