What is meant by the idea of “Cradle to Cradle?” What is the difference between technonutrients and bionutrients and how can we safely recycle both? How can we turn sewage treatment plants into nutrient management plants? What is happening in China? McDonough says, “Things are designed to either go back to biology or back to technology without contaminating each other. . . Technonutrients can be recaptured to be reutilized forever, in safe healthy ways.” He tells us that we can and must design things to go back into an intelligent material pool for human benefit without contaminating the environment.