Check out this full version of the story from our buddy Thomas Bulfinch:
"Minerva was the goddess of wisdom, but on one occasion she did a very foolish thing; she entered into competition with Juno and Venus for the prize of beauty. It happened thus: At the nuptials of Peleus and Thetis all the gods were invited with the exception of Eris, or Discord. Enraged at her exclusion, the goddess threw a golden apple among the guests, with the inscription, "For the fairest." Thereupon Juno, Venus, and Minerva each claimed the apple. Jupiter, not willing to decide in so delicate a matter, sent the goddesses to Mount Ida, where the beautiful shepherd Paris was tending his flocks, and to him was committed the decision. The goddesses accordingly appeared before him. Juno promised him power and riches, Minerva glory and renown in war, and Venus the fairest of women for his wife, each attempting to bias his decision in her own favour. Paris decided in favour of Venus and gave her the golden apple, thus making the two other goddesses his enemies. Under the protection of Venus, Paris sailed to Greece, and was hospitably received by Menelaus, king of Sparta. Now Helen, the wife of Menelaus, was the very woman whom Venus had destined for Paris, the fairest of her sex. She had been sought as a bride by numerous suitors, and before her decision was made known, they all, at the suggestion of Ulysses, one of their number, took an oath that they would defend her from all injury and avenge her cause if necessary. She chose Menelaus, and was living with him happily when Paris became their guest. Paris, aided by Venus, persuaded her to elope with him, and carried her to Troy, whence arose the famous Trojan war, the theme of the greatest poems of antiquity, those of Homer and Virgil."