In Nature, both the Caterpillar and the Butterfly serve useful purposes and have their respective niches in ecosystems. But in order to understand the purpose served by human beings in both our Caterpillar and Butterfly phases, we must examine the human story in a broader context.
Father Thomas Berry, a Catholic priest of the Passionist order, liked to call himself an Earth Scholar. He was a deep ecologist in the footsteps of Pierre Tielhard de Chardin and he considered the Universe to be the primary self-referential reality in the material world. Father Thomas Berry said that,
"The Earth is not part of the human story, the human story is part of the Earth story…The problem is we have tried to tell the human story without telling the Earth’s story. ”
Therefore, in order to understand why we are here, our larger purpose, we need to tell the Earth's story. By that same logic, the Sun is not part of the Earth’s story, but the Earth’s story is part of the Sun’s story. Therefore, if we want to understand the Earth’s story, we need to tell the Sun’s story as well.
 Berry, Thomas, The Dream of the Earth, Counterpoint, Oct 2006, ISBN-13: 978-1578051359, http://amzn.to/240x0WZ