A man had four sons and sent each one in a different season to look at a pear tree in the distance. The first son went in winter and said the tree was ugly, while the second in spring said it was promising. The third in summer said it was beautiful, and the fourth in fall said it was ripe. The man explained that they were all right because each only saw one season, and the true essence of the tree is only seen when considering all the seasons together.