Those people who succeeded were typically temperate and reliable, and completely devoted to their business. Today, there is little connection between religious beliefs and such conduct, and if it exists it is usually negative. For these people, business is an end in itself. This is their motivation, despite the fact that this is irrational from the perspective of personal happiness. In our modern individualistic world, this spirit of capitalism might be understandable simply as adaptation, because it is so well suited to capitalism. It no longer needs the force of religious conviction because it is so necessary. However, this is the case because modern capitalism has become so powerful. It may have needed religion in order to overthrow the old economic system; this is what we need to investigate. It is hardly necessary to prove that the idea of moneymaking as a calling was not believed for whole epochs, and that capitalism was at best tolerated. It is nonsense to say that the ethic of capitalism simply reflected material conditions. Rather, it is necessary to understand the background of ideas that made people feel they had a calling to make money.
Many commentators on capitalism tend to assume or argue that its existence is inevitable, that it is fundamental to human nature, or reflects an important step in a universal series of stages. Weber's account brings such claims into question. According to Weber, the "spirit" necessary for successful capitalistic activities is not natural. Striving for profit is not the only way to approach economic activities; one could, for example, simply strive for subsistence or a traditional way of life. According to Weber, when capitalism does prosper, it does so because people have embraced and internalized certain values. These values, and not just human nature, make capitalism possible. Capitalism cannot then simply be a necessary step in the world's development, because in order for it to emerge, particular values must be present. Weber thus leaves space for the importance of ideas and culture in the history of human development.
He is also specifically replying to one approach to sociology and history, promulgated by many Marxists and often called "materialism." This approach sees all ideas and developments, including the spirit of capitalism, as a reflection or superstructure of economic situations. Economic interactions are the basis for all social institutions. Religion itself is a product of such interactions; it cannot be a driving force of history. Weber's point is that for Western civilization to ever emerge out of feudal traditionalism, it needed to embrace a new set of values. These values couldn't simply have emerged out of the economic situation; we needed these values in order to rid ourselves of that situation. The formation of the values was influenced by economic situations, but not completely caused by them. According to Weber then, the materialist view is overly simplistic and not supported by the facts. Any complete understanding of historical progress would include a multiplicity of causes, and appreciate that the causal relationship between economic situations and religious outlooks goes both ways.
It is also important to notice the ways in which Weber attempts to define concepts like traditionalism and the "spirit" of capitalism. Weber relies heavily on anecdotes and case studies in order to give a sense for what these terms might mean; his discussion of the spirit of capitalism relies extremely heavily on the writings of Benjamin Franklin. This approach has both positive and negative attributes. His examples are carefully chosen and give a good grounding to his definition. However, because they are simply examples, they can potentially be attacked as not representative of a larger ethos. Weber's characterizations have indeed been attacked by some, and he has been criticized for not relying on more quantitative surveys.