Since its first publication in 1836, the popularity of the poem “Porphyria’s Lover” among readers and critics hasn’t waned. It’s written in the form of a dramatic monologue, whose speaker describes why and how he strangled his beloved to death on a stormy night. Though the cold-hearted murder of the woman causes much discomfort to the readers, the insane speaker finds nothing wrong with his brutal act. Instead, he justifies it in a number of ways.
For over one hundred and fifty years, the question of why Porphyria’s lover killed her has perplexed the readers of the poem. He loved Porphyria, and he knew that she loved him too, yet he killed her. Why?
It seems that the speaker and Porphyria must have known each other for quite some time. There must have been an illicit relationship between them. But, according to the speaker, Porphyria, for her “pride, and vainer ties,” wouldn’t set her “struggling passion free.” This suggests that though she loved him, she wouldn’t make love with him and accept him “for ever.” This could have been because of some personal reasons or social concerns.
The narrator had always wished to win Porphyria’s love "for ever." That night Porphyria took the initiative to express her love for him, quite passionately. At first, she put his arm around her waist, and then she rested his chin over her "smooth white shoulder bare." Her lover was gladly surprised. He said,
...at last I knew
Porphyria worshipped me; surprise
Made my heart swell, and still it grew
While I debated what to do.
The surprised speaker felt “happy and proud.” Nevertheless, he didn't know how he should react. He pondered hard over it.
At that moment, Porphyria was in his arms, loving and caressing him. This was the perfect moment for him, he thought:
That moment she was mine, mine, fair,
Perfectly pure and good . . .
He didn't want to lose that moment and wished to eternalize it. He feared she might not feel the same way she felt for him the next day as she did that night.
His was an apparently insane mind, for he decided to kill her. By doing so, he thought, he might be able to seize that moment forever. If Porphyria died while she was united with him, he would never lose her. Convinced by this weird idea, he instantly strangled his lover to death with her own long hair.
The speaker, then, justified his deed in a number of ways. He opened her eyelids and said her blue eyes “laughed... without a stain.” He was "quite sure she felt no pain." To him, her dead eyes and face expressed approval of his deed.
He further explained that by murdering her, he had actually fulfilled Porphyria's wish:
The smiling rosy little head,
So glad it has its utmost will . . .
One thing is absolutely certain—that he didn't kill her out of revenge or hatred. Though it would sound utterly weird and crazy to any sane person, Porphyria’s lover killed her to immortalize the moment of their union, and, in this way, fulfill what he saw as the wish of them both.