We do not need to invent sustainable human communities. We can learn from societies that have lived sustainably for centuries. We can also model communities after nature's ecosystems, which are sustainable communities of plants, animals, and microorganisms. Since the outstanding characteristic of the biosphere is its inherent ability to sustain life, a sustainable human community must be designed in such a manner that its technologies and social institutions honor, support, and cooperate with nature's inherent ability to sustain life.