The Iroquois people have a creation story that explains the creation of the world and the origins of human beings. According to this story, the world was created on the back of a turtle, and the first human beings were twin brothers. The Iroquois honor both twins in this story because they are seen as the creators of the world and the founders of their society.
The two twins, one good and one evil, are seen as complementary forces in the world and in human nature. The good twin is associated with light, life and fertility, while the evil twin is associated with darkness, death, and destruction. Both twins are needed to maintain the balance and harmony of the world and of human life. The good twin's actions bring growth, and the evil twin's actions bring change and renewal.
Additionally, honoring both twins also reflects the Iroquois belief in the importance of balance in all things and the idea that everything has a positive and negative aspect. The Iroquois people see the world as a delicate balance of good and evil, and by honoring both twins, they are recognizing the importance of both forces in the world.
In summary, the Iroquois honor both twins in the world on the turtle's back because they are seen as the creators of the world and the founders of their society, and also because they believe that both twins are needed to maintain the balance and harmony of the world and of human life.