Sociopaths in literature: Byron's "Lara"

From Byron's "Lara":

He stood a stranger in this breathing world,
An erring spirit from another hurled;
A thing of dark imaginings, that shaped
By choice the perils he by chance escaped;
. . .
Too high for common selfishness, he could
At times resign his own for others' good,
But not in pity, not because he ought,
But in some strange perversity of thought,
That sway'd him onward with a secret pride
To do what few or none would do beside;
And this same impulse would, in tempting time,
Mislead his spirit equally to crime;
So much he soar'd beyond, or sunk beneath
The men with whom he felt condemn'd to breathe,
And long'd by good or ill to separate
Himself from all who shared his mortal state;
. . .
'Tis true, with other men their path he walk'd,
And like the rest in seeming did and talk'd,
Nor outraged Reason's rules by flaw nor start,
His madness was not of the head, but heart;
. . .
He had (if 'twere not nature's boon) an art
Of fixing memory on another's heart:
It was not love, perchance — nor hate — nor aught
That words can image to express the thought;
But they who saw him did not see in vain,
And once beheld, would ask of him again:
And those to whom he spake remember'd well,
And on the words, however light, would dwell.
None knew nor how, nor why, but he entwined
Himself perforce around the hearer's mind;
There he was stamp'd, in liking, or in hate,
If greeted once; however brief the date
That friendship, pity, or aversion knew,
Still there within the inmost thought he grew.
You could not penetrate his soul, but found
Despite your wonder, to your own he wound.
His presence haunted still; and from the breast
He forced an all-unwilling interest;
Vain was the struggle in that mental net,
His spirit seem'd to dare you to forget!