Theme in Macbeth: "Fair Is Foul, Foul Is Fair"

Macbeth's theme in one word is EQUIVOCATION (of double or doubtful meaning, questionable, ambiguous). Equivocation is prevalent throughout the play. Lady Macbeth uses it a lot, and suggests it to her husband when she says "...look like the innocent flower / But be the serpent under 't..." (Act I, Scene 5, 64-65)
In other words, the idea or theme in the play is "Fair is foul, foul is fair." Basically, this means that appearances can be deceiving. What appears to be good can be bad, and this is seen in such things as the deceptive facade of Lady Macbeth and in the predictions of the witches.…