Comparative
In linguistics, the comparative is a syntactic construction that serves to express a comparison between two (or more) entities or groups of entities in quality, or degree. See comparison (grammar) for an overview of comparison, as well as positive and superlative degrees of comparison.
Comparative Literature
Comparative literature is an academic field dealing with the study of literature and cultural expression across linguistic, national, and disciplinary boundaries. Comparative literature "performs a role similar to that of the study of international relations, but works with languages and artistic traditions, so as to understand cultures 'from the inside'". While most frequently practiced with works of different languages, comparative literature may also be performed on works of the same language if the works originate from different nations or cultures among which that language is spoken.
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
Literature is news that stays news.
Ezra Pound, ABC of Reading (1934), Ch. 8
Theory
The successful development of science requires a proper balance between the method of building up from observations and the method of deducing by pure reasoning from speculative assumptions...
Paul Dirac, “Physical Science and Philosophy”, Nature (1937) Vol. 139, p. 1001.
Literature
The death of Dr. Hudson is a loss to the republick of letters.
William King, letter (Jan. 7, 1719). Same phrase occurs in the Spectator. Commonwealth of letters is used by Addison, Spectator, No. 529. Nov. 6, 1712.