The original story of "The Little Mermaid" by Christian Andersen

Part 8

Increasingly she grew to like human beings, and more and more she longed to live among them. Their world seemed so much wider than her own, for they could skim over the sea in ships, and mount up into the lofty peaks high over the clouds, and their lands stretched out in woods and fields farther than the eye could see.
There was so much she wanted to know.
Her sisters could not answer all her questions, so she asked her old grandmother, who knew about the"upper world," which was what she said was the right name for the countries above the sea.

"If men aren't drowned," the little mermaid asked, "do they live on forever? Don't they die, as we do down here in the sea?"

"Yes," the old lady said, "they too must die, and their lifetimes are even shorter than ours. We can live to be three hundred years old, but when we perish we turn into mere foam on the sea, and haven't even a grave down here among our dear ones. We have no immortal soul, no life hereafter. We are like the green seaweed - once cut down, it never grows again.
Human beings, on the contray, have a soul which lives forever, long after their bodies have turned to clay. It rises through thin air, up to the shining stars.
Just as we rise through water to see the lands on earth, so men rise up to beautiful places unknown, which we shall never see. "

"Why weren't we given an immortal soul?" The little mermaid sadly asked. "I would gladly give up my three hundred years if I could be a human being only for a day, and later share in that heavenly realm."

"You must not think about that," said the old lady. "We fare much more happily and are much better off than the folk up there."

"Then I must also die and float as foam upon the sea, not hearing the music of the waves, and seeing neither the beautiful flowers nor the red sun! Can't I do anything at all to win an immortal soul?"

"No," her grandmother answered, "not unless a human being loved you so much that you meant more to him than his father and mother. If his every thought and his whole heart cleaved to you so that he would let a priest join his right hand to yours and would promise to be faithful here and throughout all eternity, then his soul would dwell in your body, and you would share in the happiness of mankind. He would give you a soul and yet keep his own.
But that can never come to pass.
The very thing that is your greatest beauty here in the sea - your fish tail - would be considered ugly on land.
They have such poor taste that to be thought beautiful there you have to have two awkward props which they call legs."

The little mermaid sighed and looked unhappily at her fish tail.

"Come, let us be gay!" The old lady said. "Let us leap and bound throughout the three hundred years that we have to live. Surely that is time and to spare, and afterwards we shall be glad enough to rest in our graves. - we are holding a court ball this evening."