I

Bill Plotkin, American depth psychologist, wilderness guide and founder of the Animas Valley Institute. He presents the model in Soulcraft (2003) and most fully in Nature and the Human Soul (2008). He calls it the "eco-soulcentric developmental wheel" (the Soulcentric Developmental Wheel), and it is the life cycle of a person who matures toward a soul-rooted, nature-connected adulthood.

The eight stages, in order:

1. Innocent in the Nest (early childhood)
2. Explorer in the Cocoon (middle childhood)
3. Thespian at the Threshold (early adolescence)
4. Wanderer in the Wilderness (late adolescence to early adulthood)
5. Soul Apprentice at the Wellspring (soul initiation begins)
6. Artisan in the Cave (giving the soul's gift form)
7. Master in the Sea (mature adult, cultural contribution)
8. Sage / Elder (elderhood)