In the delineation of character Shakespeare has no rivals. He creates no monsters. His characters do not act without reason, without motive.
Iago had his reasons. In Caliban, nature was not destroyed—and Lady Macbeth certifies that the woman still was in her heart, by saying:
"Had he not resembled my father as he slept, I had done it."
Shakespeare's characters act from within. They are centres of energy. They are not pushed by unseen hands, or pulled by unseen strings. They have objects, desires. They are persons—real, living beings.
Few dramatists succeed in getting their characters loose from the canvas—their backs stick to the wall—they do not have free and independent action—they have no background, no unexpressed motives—no untold desires. They lack the complexity of the real.
Shakespeare makes the character true to itself. Christopher Sly, surrounded by the luxuries of a lord, true to his station, calls for a pot of the smallest ale.
Take one expression by Lady Macbeth. You remember that after the murder is discovered—after the alarm bell is rung—she appears upon the scene wanting to know what has happened. Macduff refuses to tell her, saying that the slightest word would murder as it fell. At this moment Banquo comes upon the scene and Macduff cries out to him:
"Our royal master's murdered."
What does Lady Macbeth then say? She in fact makes a confession of guilt. The weak point in the terrible tragedy is that Duncan was murdered in Macbeth's castle. So when Lady Macbeth hears what they suppose is news to her, she cries:
"What! In our house!"