Imagine a cherry tree in full bloom, its roots sunk into rich earth and its branches covered with thousands of blossoms, all emitting a lovely fragrance and containing thousands of seeds capable of producing many more cherry trees. The petals begin to fall, covering the ground in a blanket of white flowers and scattering the seeds everywhere.

Some of the seeds will take root, but the vast majority will simply break down along with the spent petals, becoming part of the soil that nourishes the tree — along with thousands of other plants and animals.

Looking at this scene, do we shake our heads at the senseless waste, mess and inefficiency? Does it look like the tree is working too hard, showing signs of strain or collapse? Of course not. But why not?

Well, for one thing, because the whole process is beautiful, abundant and pleasure producing: We enjoy seeing and smelling the trees in bloom, we’re pleased by the idea of the trees multiplying (and producing delicious cherries), and everyone for miles around seems to benefit in the process.

The entire lifecycle of the cherry tree is rewarding, and the only “waste” involved is an abundant sort of nutrient cycling that only leads to more good things. Best of all, this show of productivity and generosity seems to come quite naturally to the tree. It shows no signs of discontent or resentment — in fact, it looks like it could keep this up indefinitely with nothing but good, sustainable outcomes.

The cherry-tree scenario is one model that renowned designer and sustainable-development expert William McDonough uses to illustrate how healthy, sustainable systems are supposed to work. “Every last particle contributes in some way to the health of a thriving ecosystem,” he writes in his essay (coauthored with Michael Braungart), “The Extravagant Gesture: Nature, Design and the Transformation of Human Industry”