This impressive and original scene prepares the reader to wonder why it is that Manfred is so desirous to drink of Lethe.  He has acquired dominion over spirits, and he finds, in the possession of the power, that knowledge has only brought him sorrow.  They tell him he is immortal, and what he suffers is as inextinguishable as his own being: why should he desire forgetfulness?—Has he not committed a great secret sin?  What is it?—He alludes to his sister, and in his subsequent interview with the witch we gather a dreadful meaning concerning her fate.  Her blood has been shed, not by his hand nor in punishment, but in the shadow and occultations of some unutterable crime and mystery.

She was like me in lineaments; her eyes,
Her hair, her features, all to the very tone
Even of her voice, they said were like to mine,
But soften’d all and temper’d into beauty.
She had the same lone thoughts and wanderings,
The quest of hidden knowledge, and a mind
To comprehend the universe; nor these
Alone, but with them gentler powers than mine,
Pity, and smiles, and tears, which I had not;
And tenderness—but that I had for her;
Humility, and that I never had:
Her faults were mine—her virtues were her own;
I lov’d her and—destroy’d her—

WITCH

With thy hand?

MANFRED

Not with my hand, but heart, which broke her heart.
It gaz’d on mine, and withered.  I have shed
Blood, but not hers, and yet her blood was shed;—
I saw, and could not stanch it.

There is in this little scene, perhaps, the deepest pathos ever expressed; but it is not of its beauty that I am treating; my object in noticing it here is, that it may be considered in connection with that where Manfred appears with his insatiate thirst of knowledge, and manacled with guilt.  It indicates that his sister, Astarte, had been self-sacrificed in the pursuit of their magical knowledge.  Human sacrifices were supposed to be among the initiate propitiations of the demons that have their purposes in magic—as well as compacts signed with the blood of the self-sold.  There was also a dark Egyptian art, of which the knowledge and the efficacy could only be obtained by the novitiate’s procuring a voluntary victim—the dearest object to himself and to whom he also was the dearest;2 and the primary spring of Byron’s tragedy lies, I conceive, in a sacrifice of that kind having been performed, without obtaining that happiness which the votary expected would be found in the knowledge and power purchased at such a price.  His sister was sacrificed in vain.  The manner of the sacrifice is not divulged, but it is darkly intimated to have been done amid the perturbations of something horrible.