"Or art thou but / A dagger of the mind, a false creation, / Proceeding from the heat-oppressèd brain?"
"Dagger of the mind" can read in two ways. First, there's the literal contrast of tangible reality and Macbeth's imagination. Second, you have metaphor of Macbeth's guilt—and doubt—manifesting itself as a vision as he waits upon the signal from his wife. False in this context plays upon a number of meanings. While the primary reading is unreal, shades of deceitful, inconstant; not to be trusted are equally applicable. Macbeth acknowledges that the dagger that has appeared could be a trick of his imagination (in this case, induced by a fever). Proceeding is used in its meaning of "issuing or emanating," while heat-oppressèd is Shakespeare's poetic way of saying "fevered." The usage of fever is another simple but amazingly effective piece of imagery in this speech. Fever is a symptom of a disease in its literal meaning. As a metaphor, fever denotes a state of heightened or intense emotion or activity. The disease, in this instance, is ambition.
"Dagger of the mind" can read in two ways. First, there's the literal contrast of tangible reality and Macbeth's imagination. Second, you have metaphor of Macbeth's guilt—and doubt—manifesting itself as a vision as he waits upon the signal from his wife. False in this context plays upon a number of meanings. While the primary reading is unreal, shades of deceitful, inconstant; not to be trusted are equally applicable. Macbeth acknowledges that the dagger that has appeared could be a trick of his imagination (in this case, induced by a fever). Proceeding is used in its meaning of "issuing or emanating," while heat-oppressèd is Shakespeare's poetic way of saying "fevered." The usage of fever is another simple but amazingly effective piece of imagery in this speech. Fever is a symptom of a disease in its literal meaning. As a metaphor, fever denotes a state of heightened or intense emotion or activity. The disease, in this instance, is ambition.