Energy plays a fundamental role in shaping the human condition. People's need for energy is essential for survival, so it is not surprising that energy production and consumption are some of the most important activities of human life. Indeed, it has been argued that energy is the key "to the advance of civilization," that the evolution of human societies is dependent on the conversion of energy for human use. Few people have questioned the long-held assumption that standard of living and quality of civilization are proportional to the quantity of energy a society uses. However imprecise it may be, most people still accept the steadfast formula: energy=progress=civilization.