When the Porter lets in Macduff and Lenox, he seems to have admitted also a very garish and vulgar kind of day, that displays loosely some infirmities of men, unconscious of the more awful crime within,--a very broad and unequivocal daylight that lies sharply on all objects without toning them. The Porter's disquisition upon drinking and lechery is apparently superfluous and revolting, but it is really well conceived; for we want something to carry our mood as far as possible away from Duncan's chamber and from all thoughts about discovering the deed, because Macbeth is about to enter. "Our knocking has awaked him." Then our feeling, which has gained a temporary relief, is able to take up again the awful clew, and to wait during Macbeth's feigned unconsciousness till Macduff bursts upon us with his horror. Moreover, the carousing which the Porter mentions was the cover to Macbeth's opportunity, and just keeps the night alive in our memory, while we think how innocently drunk the whole household was to provide a human weakness for an act of death. Macbeth enters, whose wife conceived the stratagem of the drinking, and soon the result of it arrives. An after-clap of Hell settles back on the Porter's traces; but he has performed his function by letting life and human nature in upon the sexless and monstrous scene, and may now vacate his post.
Still, the Porter is conventionally vulgar, and cannot be accepted by a taste that is more fastidious than the world itself is. But, if the world chooses to be vulgar, why needed Shakspeare to have imported this base touch of realism into his art? Only by the permission of Humor, and the justification of an exigency to drag our feelings back to life by the handiest strand, however coarse it may be. And after he had invented that thrilling moment of the knocking at the gate, he cannot get along without the house-porter, who is the only one awake enough to let honest Nature in. So we must take him as he is, and admire the poet who did not send the Muse of Tragedy to draw the bolt.
The Agamemnon of Æschylus reaches a breathless moment of suspense, when Clytemnestra has left the scene to plan the murder of her husband, and the Chorus, shuddering with its divination of the deed, expresses our expectation. All at once a stifled exclamation struggles out from the interior of the palace: the Chorus whispers, "Hush! who is it that cries out, 'A blow'?" and the play soon closes with the sombre feeling unrelieved. Nothing intervenes to assist the spectators back to life, and to the other persons whose interests implicate them so deeply in the plot. There is but one interest and one action in a Greek Tragedy, and when that is reached the nature of the scene is exhausted; the poet has no more to say, and is not conscious of any craving for variety in his listeners. His play was an artistic embodiment of the current religious ideas, and so far was secluded, as the modern pulpit is, from manifold life. It is not possible to discover a place in these solemn developments of Fate, where a feeling of Humor could intrude. The Chorus, listening to the blow, intervenes instead of a Porter. It is the voice of an audience conscious of the crime. So is a modern audience conscious of Macbeth's crime, but that consciousness is itself the Chorus, whose ancient function is distributed through the silent hearts of the spectators, who are thus permitted to mingle in every awful occurrence, and therefore need to be restored again to the ordinary world of justice and emotion.