Leslie White, Author of the Evolution of Culture

Leslie White, author of The Evolution of Culture: The Development of Civilization to the Fall of Rome (1959), attempted to create a theory explaining the entire history of humanity. The most important factor in his theory is technology: Social systems are determined by technological systems, wrote White in his book, echoing the earlier theory of Lewis Henry Morgan. As measure of society advancement, he proposed the measure of a society's energy consumption. He differentiates between five stages of human development. In first, people use energy of their own muscles. In second, they use energy of domestication of animals. In third, they use the energy of plants (so White refers to agricultural revolution here). In fourth, they learn to use the energy of natural resources: coal, oil, gas. In fifth, they harness the nuclear energy. White introduced a formulae, P=E*T, where E is a measure of energy consumed, and T is the measure of efficiency of technical factors utilising the energy. This theory is similar to Russian astronomer Nikolai Kardashev's later theory of the Kardashev scale.
Julian Steward, author of Theory of Culture Change: The Methodology of Multilinear Evolution (1955, reprinted 1979), created the theory of "multilinear" evolution which examined the way in which societies adapted to their environment. This approach was more nuanced than White's theory of "unilinear evolution." Steward on the other hand rejected the 19th-century notion of progress, and instead called attention to the Darwinian notion of "adaptation", arguing that all societies had to adapt to their environment in some way. He argued that different adaptations could be studied through the examination of the specific resources a society exploited, the technology the society relied on to exploit these resources, and the organisation of human labour. He further argued that different environments and technologies would require different kinds of adaptations, and that as the resource base or