Culture
Culture () is the social behavior and norms found in human societies. Culture is considered a central concept in anthropology, encompassing the range of phenomena that are transmitted through social learning in human societies. Some aspects of human behavior, social practices such as culture, expressive forms such as art, music, dance, ritual, religion, and technologies such as tool usage, cooking, shelter, and clothing are said to be cultural universals, found in all human societies. The concept of material culture covers the physical expressions of culture, such as technology, architecture and art, whereas the immaterial aspects of culture such as principles of social organization (including practices of political organization and social institutions), mythology, philosophy, literature (both written and oral), and science comprise the intangible cultural heritage of a society.
Literature
Literature, most generically, is any body of written works. More restrictively, literature writing is considered to be an art form, or any single writing deemed to have artistic or intellectual value, often due to deploying language in ways that differ from ordinary usage.
Theory
A theory is a contemplative and rational type of abstract or generalizing thinking, or the results of such thinking. Depending on the context, the results might, for example, include generalized explanations of how nature works. The word has its roots in ancient Greek, but in modern use it has taken on several related meanings.
Literature
There is first the literature of knowledge, and secondly, the literature of power. The function of the first is—to teach; the function of the second is—to move, the first is a rudder, the second an oar or a sail. The first speaks to the mere discursive understanding; the second speaks ultimately, it may happen, to the higher understanding or reason, but always through affections of pleasure and sympathy.
Thomas De Quincey, Essays on the Poets, Alexander Pope.