Sentence:  Does this mean, then, that there can be no such thing as a <WSD>theory</WSD> of literature? 
Meaning of the word marked with <WSD> tags:  A coherent statement or set of ideas that explains observed facts or phenomena and correctly predicts new facts or phenomena not previously observed, or which sets out the laws and principles of something known or observed; a hypothesis confirmed by observation, experiment etc. (from 17th c.)