Beauty and the Beast

An enchantress, disguised as an old beggar, offers a rose to a young prince, Adam, in exchange for shelter in his castle from the cold, but Adam refuses. For his arrogance, the enchantress transforms him into a beast and places a spell on the castle. She gives him a magic mirror that enables him to view faraway events, along with the enchanted rose that she had offered. To break the spell, the prince must learn to love another and earn her love in return before the rose's last petal falls on his 21st birthday. If he fails, he will remain a beast forever.
Ten years later, a young bookworm girl named Belle is bored of her village life and seeks excitement. Because of her nonconformist ideals, she is ridiculed by everyone except her father Maurice (an odd inventor), the town bookseller, and a vain muscular hunter named Gaston. Despite being popular with the townsfolk, Gaston is determined to marry Belle. She repeatedly rejects his advances.
Maurice and his horse Phillipe get lost in the forest while traveling to a fair to present his newest invention, a wood-chopping machine. After being chased by a pack of wolves, he comes across the Beast's castle. Inside, he meets LumiÃ¨re the candlestick, Cogsworth the clock, Mrs. Potts the teapot, and her son Chip the teacup. However, the Beast quickly discovers and detains Maurice. After Phillipe leads Belle to the Beast's castle, she offers to take her father's place. Over her father's objections, the Beast accepts Belle's offer. While Gaston sulks over Belle's rejection, Maurice returns to town but is unable to convince the others to save Belle from the Beast.
The Beast sulks in his room when Belle refuses to have dinner with him that night. Despite this, LumiÃ¨re offers her a meal. While he and Cogsworth also give her a tour of the castle, she wanders into the forbidden West Wing. When the Beast inadvertently chases her into the forest by frightening her in frustration, Belle encounters the pack of wolves. After the Beast is injured while fending them off, Belle thanks him for saving her life. He begins to develop feelings for her while she nurses his wounds and he delights her by showing his extensive library. While the two begin to bond in the Beast's castle, in the village Gaston pays Monsieur D'Arque to send Maurice to the town's insane asylum if Belle refuses Gaston's proposal again.
Sharing a romantic evening together, Belle tells the Beast she misses her father. He lets her use his magic mirror to see him. She sees Maurice dying in the woods trying to reach the castle. The Beast lets her go out to save him and he gives her the mirror to remember him by. She finds Maurice and brings him home. As Gaston is about to bring Maurice to the insane asylum, Belle proves Maurice's sanity by showing the Beast with the mirror. Realizing that Belle loves the Beast, Gaston convinces the villagers that the Beast is a man-eating monster and leads them to the castle to kill him.
Having stowed away into Belle's baggage, Chip helps Maurice and Belle escape from confinement. Gaston fights the Beast while the servants fend off the villagers. The Beast initially is too depressed to fight back, but perks up after seeing Belle return to the castle. He defeats Gaston on the rooftops, and spares Gaston's life by ordering him to leave. However, when Gaston mortally wounds the Beast, he loses his footing and falls to his death.[a] Belle professes her love for the Beast, who dies before the last rose petal falls. With the spell broken, the Beast revives and returns to his true form. The servants resume their human forms and the castle is restored to its former glory. Belle dances with Adam in the ballroom as everyone watches in delight.

Question: To break the spell, what must the beast learn?
Answer: Love