Arboreal Thought: Weightless Spirits Willingly Fly with a Persuasive, Heavenly Embrace (Hardcover) (ISBN-13: 9781490785158)

My idea of arboreal thought is an analogy based on the arboreal hypothesis that suggests a ground-running biped of some kind that adapted itself to living in trees. The hypothesis suggests that the biped began climbing trees, then leaping branches, then parachuting branches, and finally developing feathered, flapping wings to fly.