Medieval attitudes towards literature were often guided by Christian teaching. The works that were applauded were those which communicated some moral thought. Literature was not meant to be read for the pleasure it would provide in diversion; it was supposed to be constructive towards a further end. It was read for moral profit. This can still be argued about all literature on a different level. Even Boccaccio claims that the Decameron is not simply for amusement, that the readers can find in it what they please, which may very well include a lesson on life. What is distinct about the Middle Ages is that the end was connected with a certain view of "right," extending the dominion of the Church or of a moral code.
The understanding of poetry in the Middle Ages depended a great deal on Horace's definition in the Ars poetica. The best poetry is that which combines profit and pleasure. Within this view there is a greater assumption: the separation between content (truth) and form, echoing the same separation that existed in medieval Christian thought, or in Platonic philosophy. (The Aristotelian view of literature, in contrast, would allow for a fusion that gave art or mimesis independent value.) The surface, the external, was devalued. The poem was like a nut that had to be broken: the mature person searched for the inner truth. There are indications that literary purpose was somewhat polarized: some works were written merely to entertain while others were just meant to be useful. Augustine makes a further distinction between those which are meant to provide delight - called fabula - and those which are simply meant to deceive. What was the conception of literary pleasure? Olson separates the generalizations into two groups:
a) formal considerations: pleasure comes from appreciation of style, verbal beauty, astute employment of rhetoric.
b) narrative itself: literal level of detail or plot. Pleasure in close imitation and recognition of the real; realism.
More specifically, we may ask what was thought to be the nature of literary pleasure itself, the response of the reader to the text? Delight was seen as possession, rest (regardless of an ultimate spiritual end). The desire for something perceived as good is thus fulfilled. This can be, according to Aquinas, the imperfect happiness of this world, or the ultimate union with God. Sensual delights can hinder and blur the way to God. How can pleasure itself be profitable? One view was that it could serve as an enticement to learning, allow truths to seep in, masked in sweet coverings. The best literature, therefore, would still be that which provides profit and pleasure. Learning good style could cultivate effort and patience and moral content would teach virtue.
And yet, this still does not allow to simply identify profit and pleasure. Olson's attempt to clarify this point is based on medical and psychological grounds: it acknowledges the medieval "pragmatic" project, which gives pleasure credit with relation to a further end, health which, in turn, can allow more profitable or "good" actions.
Olson, Glending. Literature as Recreation in the Later Middle Ages. Ithaca: Cornell University Press, 1982.