ROSS               Gentlemen, rise. His highness is not well.

LADY              Sit, worthy friends. My lord is often thus,

And hath been from his youth. Pray you keep seat.

The fit is momentary. Upon a thought

He will again be well. If much you note him,

You shall offend him and extend his passion.

Feed, and regard him not. [Aside to Macbeth] Are you a man?

MACBETH      [aside to his Lady] Ay, and a bold one, that dare look on that

Which might appal the devil.           (3.4.50-58)

Ross is being helpful, the fixer, taking control, perhaps a bit precipitately (but it’s an indication of the state that Macbeth’s in): Gentlemen, rise. His highness is not well. He tries to break up the feast, get rid of everyone. Lady Macbeth pulls rank, trying in turn to wrestle back the initiative as well as downplaying what’s going on by addressing the company as worthy friends, not the more formal gentlemen, and referring to my lord, my husband, rather than the less personal his highness. But it’s a spectacularly ill-judged intervention, and signals that she, too, is losing her touch. My lord is often thus, and hath been from his youth. What? this is either transparently a lie, or else it’s a complete undermining of Macbeth’s power and authority: you mean he’s often like this, well, mad, beside himself, that it’s a lifelong thing? Alright, so you’re implying he’s been able to conceal it, to manage it until now, but, what else is he hiding? Not helpful. Pray you keep seat: don’t mind him! don’t get up! stay where you are! it’ll all be fine! the fit is momentary. (Fit an especially unhelpful word in a culture frightened by epilepsy, for example, although fit doesn’t just suggest that here.) He’s just having a bit of a funny turn, a moment, and upon a thought, before you know it, he will again be well. Another slightly desperate intervention: if much you note him, you shall offend him and extend his passion. Don’t stare! Talk amongst yourselves! Act normally and ignore him! if you pay him too much attention, note him too much, you shall offend him: he’ll get upset and extend his passion, so that this—thing—lasts longer. Nothing to see here! Just get on with your dinner! Feed, and regard him not. (What’s Macbeth doing? Frozen, horrified, staring at thin air? Shaking? Face in hands? Lots of options…)

Then the jab to the ribs, the appalled hiss, going for her accustomed needle straight away: are you a man? Pull yourself together, what the hell is going on? And he hears her alright, and punches back, lashes out in terror: ay, I am a man, and a bold one, that dare look on that which might appal the devil. Sheer horror, in a play full of terrible sights, real and imagined—and confirmation that he can see this appalling thing, but no one else can, not even his wife. He’s on his own.