The more I probe the hardest questions about the future of energy and our best shot at sustainability, the more I am convinced that the real questions are not about technology, but about human nature. We have all the technology we need to make homes that produce their own energy. We know how to build high-efficiency rail and sailing ships. We know how to grow food organically and sustainably. We have the science to create economic systems that internalize all effects and operate in a beneficial manner. We've had the quantitative knowledge for decades that we would eventually go into resource and environmental overshoot.