"A Man's Reach Should Exceed His Grasp"

Context: Browning imagined this speech as being spoken by the Italian painter, Andrea del Sarto, who gained fame in the early sixteenth century. Andrea is speaking to his wife and reflects upon his stature as a painter. So perfect had his technical skill become, that he was called "the faultless painter." But he lacked the depth of conviction and intensity of feeling that a great artist must have. He has technical perfection, but lacks feeling; other painters he knows of have greatness of soul, but lack the skill that Andrea possesses. He sees in this situation a comment upon life: there is always something missing in human effort so that perfection is never attainable. Yet a man must strive for perfection.

Ah, but a man's reach should exceed his grasp,
Or what's a heaven for?
. . .
I know both what I want and what might gain,
And yet how profitless to know, to sigh
"Had I been two, another and myself. . . ."