A father sent his four sons each in a different season to look at a pear tree in the distance to teach them not to judge things too quickly. 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 in blossom, and the fourth in fall said it was full of ripe fruit. The father explained that you cannot truly understand something by only seeing one season, and must experience all to appreciate its whole essence.