In the "Is this a Dagger?" scene Macbeth is not mad and there are quotes to support that. When Macbeth asks himself, "or art thou but/ A dagger of the mind,"(2.1. 37-38) it is clear that he has a grasp of reality and that he is sane enough to ask himself a question based on his own thoughts. In addition when Macbeth thinks, "There's no such thing:/ It is the bloody business which informs/ Thus to mine eyes." (2.1. 47-49) it is evident that Macbeth considers his vision as more of a message. With examination of these quotes and the entire soliloquy it is obvious that Macbeth is not crazy.
If I was a director of a "Is this a Dagger?" scene I would have the Macbeth actor use a prop dagger in his soliloquy. Macbeth needs a dagger because when he says, "As this which now I draw." (2.1. 41) it only makes sense that an actor would pull out a dagger. Even if Macbeth actually has a dagger in his hand at this point his sanity will still be questionable because he still won't have a dagger in his hand at the beginning. A dagger prop should be used in this soliloquy for the benefit of the visual performance a director would be trying to display.
