The term religion refers to a wide range of beliefs and practices. It can be seen in different forms in all cultures. The emergence of a wide variety of cultures and the growth of scientific history, archaeology, anthropology, and the other social sciences in the 19th century prompted an interest in more detailed study of the various forms of religion. In particular, the development of comparative theories prepared the way for a better understanding of religion as a social phenomenon and the nature of its diversity.
The early historical religions, such as those of ancient Egypt and Mesopotamia, included the belief in a supreme god or deities as well as the worship of various idols. These grew in complexity over the centuries to incorporate such things as myths, stories about creation and a set of laws for human behavior. Some historians and sociologists, such as Max Weber (1864-1920), analyzed the impact of these religions on their societies and how they were used by those in power. The German philosopher Ludwig Feuerbach (1804-72) propounded a view of religion as the projection of the aspirations of humans. Other scholars like Paul Tillich (1907-88) defined religion functionally as whatever beliefs and practices generate social cohesion and provide orientation for life.
These and other theories of religion provided the framework for the modern study of religion. However, these theories did not necessarily provide a clear definition of the concept. This led to disagreements about what constituted religion. Some argued that only what was believed in or done to please an all-powerful god could be considered a religion. Others took a more pragmatic approach to the question and looked for a definition that would accommodate the great diversity of religious practice.
Some, like the French Abbe Bergier (1718-90), saw primitive religions as a belief in spirits that caused or were caused by natural events. He thought that this was the precursor of animism and, later, of monotheism.
Another approach was taken by the German sociologists Emil Durkheim (1858-1914) and Karl Marx (1818-83) who studied the social causes of religion. Durkheim thought that religion was a way to express the naivety and helplessness of the working class and that it helped maintain patterns of inequality in society. Marx viewed religion as a tool of the ruling class to control and manipulate the masses.
The most common definitions today take a more polythetic approach to the idea of religion. These approaches look for a set of characteristics that seem to be common in religions across cultures. Such an approach can be useful in sorting out the differences between cultural types, but it does not necessarily prove that any one definition is correct. This is why, for example, it is often said that you can’t correct a stipulative definition (such as the ice-skating example above) by pointing out that it does not accurately categorize Buddhism or capitalism.