In the third stanza, the speaker departs from the general and enters the specific, addressing his beloved and recalling the moment when love destroyed his heart, enabling him to understand that which he now writes in his poem; the instant he saw his beloved, love shattered his heart like glass. The final stanza offers a kind of moral for the poem, opening in a homiletic tone (“nothing can to nothing fall, / Nor any place be empty quite”) and detailing what happens to a heart after it has been shattered by the force of love. The heart remains, the speaker claims, in the breast, like shards of a broken mirror, able to reflect lesser emotions, such as hope and affection, but never again to love.
Throughout, “The Broken Heart” typifies the quality of Donne’s metaphysical poems. It is often difficult to understand the speaker’s language or to see quite where he is coming from (the opening of the poem is particularly difficult), but once the basic idea is grasped, most of the conceptual elements of the poem fall easily into place. It is remarkable for its unusual conception of love—not many poets would compare love to death by a violent disease—and for the surprising angles from which the speaker approaches that conception.