Granville-Barker, Harley. "Julius Caesar."
Prefaces to Shakespeare. Vol. 2. Princeton, N.J.: Princeton UP, 1947. 350-412.

Thesis: Harley Granville-Barker (1877-1946) was a man of the theater—actor, director, producer, playwright, and critic. As such, he writes about costuming, staging, where an intermission may taken, and—above all—how characters can be most effectively portrayed, for he is quite sure that character is the heart of drama and that Shakespeare "finds the spiritual problem of the virtuous murderer the most interesting thing in the story" (351).

Evaluation: Granville-Barker can be very good when he is discussing how a scene develops, as in the following passage, which concerns Brutus's meeting with the conspirators:
The scene's marrow is the working of Brutus' mind, alone, in company. He is working it to some purpose now. But because it is, by disposition, a solitary mind, unused to interplay, and because the thoughts are not yet fused with emotion, that commoner currency between man and man, the scene may seem to move a little stiffly and Brutus himself to be stiff. Is not this, again, dramatically right? Would he not speak his thoughts starkly, while the rest on listen and acquiesce?—though Cassius does interpose one broken sentence of protest. They respect him, this upright, calm, self-contained man. He can command, but he cannot stir them; he is not a born leader. If the scene lacks suppleness and ease, one thought not prompting another revealingly, if it burns bright and hard, with never a flash into flame, so it would have been. But see how Shkespeare finally turns this very stiffness and suppression to a greater emtotional account, when after the silence Brutus keeps in the scene with Portia, the cry is wrung from him at last:
You are my true and honourable wife,
As dear to me as are the ruddy drops
That visit my sad heart.
For let no one imagine that the overwhelming effect of this lies in the lines themselves. It has been won by his long impassiveness; by his listening, as we listen to Portia, till he and we too are overwrought. It is won by the courage with which Shakespeare holds his dramatic course.  (354-55)
On the other hand Granville-Barker doesn't seem quite happy with the play as Shakespeare wrote it, as in the following passage about Brutus:
Brutus' soliloquies in Act II are all but pure thought, and in their place in the play, and at this stage of his development, are well enough, are very well. But—does Shakespeare feel?—you cannot conduct a tragedy to its crisis so frigidly. Had Brutus been the play's true and sole hero a way might have been found (by circling him, for instance, with episodes of passion) to sustain the emotional tension in very opposition to his stoic clam. The murder of Caesar and its sequel sweeps the play up to a passionate height. The quarrel with the passionate Cassius, and the fine device of the withheld news of Port's death, lift Brutus to an heroic height without any betrayal of the consistent nature of the man. But now [at the appearance of Caesar's ghost] we are at a standstill. Now, when we expect nemesis approaching, some deeper revelation, some glimpse of the hero's very soul, this hero stays inarticulate, or, worse, turns oracular. The picturing of him is kept to the end at a high pitch of simple beauty; but when—so we feel—the final and intimate tragic issue should open out, somehow it will not open.  (358)
This is unhelpful grouching.

Bottom Line: A highly variable reading experience.