A parable was a type of analogy which was intended to teach a lesson.
"A scorpion was walking along the bank of a river, wondering how to get to the other side. Suddenly he saw a fox. He asked the fox to take him on his back across the river. The fox said, "No, if I do that you'll sting me, and I'll drown." The scorpion assured him, "If I did that, we'd both drown." So the fox thought about it and finally agreed. So the scorpion climbed up on his back, and the fox began to swim. But halfway across the river, the scorpion stung him. As the poison filled his veins, the fox turned to the scorpion and said, "why did you do that? Now you'll drown too." "I couldn't help it," said the scorpion. "It's my nature.""He related the story to discourage Janeway from a plan she had regarding the Borg. (VOY: "Scorpion")
The Talaxian book Selected Works of Jirex contained several parables. Neelix never went to sleep without reading a parable from the book. In 2374, Tuvok informed Neelix that he would have to break his habit until power could be restored to USS Voyager's crew quarters. Neelix agreed. (VOY: "Demon")