«Mine eye and heart are at a mortal war
How to divide the conquest of thy sight».
The poet alludes to contradictions within himself when he considers his longing for the sight of the youth’s good looks and his need to love and be loved by the youth himself.
Mine eye and heart are at a mortal war
Sonnet 46 thus deals with the theme of conflict between the poet’s eyes and heart: “Mine eye and heart are at a mortal war / How to divide the conquest of thy sight.”
He says that his heart wants the youth to itself, and the eye would bar the heart from the youth as well. Legal terminology used in the sonnet reflects contemporary life in the impaneling of an impartial jury to decide the matter. A verdict is reached when the poet awards the youth’s outward appearance to the eye and his inner love to the heart.
English audio from YouTube Channel Socratica
Summary from Cliffsnotes.com