One of the standards Lewis gives to determine what constitutes good literature is whether a book has stood the test of time. He offers advice in his essay “On the Reading of Old Books.” He recommends that, for every new book one reads, one should read an old book: “It is a good rule, after reading a new book, never to allow yourself another new one till you have read an old one in between” (201-2). He continually emphasizes the superiority of the classics and great books. Additionally, he advises the average reader that, if the need arises to choose between a new or old book, the reader should choose the old because “he is an amateur and therefore much less protected than the expert against the dangers of an exclusively temporary diet” (“On the Reading of Old Books” 201). The danger in new books, he explains, is that the book is still “on trial [and must still] be tested against the great body of Christian thought down the ages, and all its hidden implications (often unsuspected by the author himself) have to be brought to light” (“On the Reading of Old Books” 201). Thus, the central reason Lewis offers for reading old as opposed to modern books is that older ones have stood the test of time, whereas modern ones have not had adequate time to be judged and deemed worthy to be read.

        Lewis offers further evidence for the value of old books: those that have stood the test of time are valuable because they reveal the mistakes of the era in which they were written. By learning from these past mistakes, readers are better equipped to avoid similar mistakes in their own age.  He explains that, since each age contains a particular dominant view of life, a book from that era is particularly good at both “seeing certain truths and . . . liable to [make] certain mistakes (“On the Reading of Old Books” 202). Everyone needs “books that will correct the characteristic mistakes of [their] own period. And that means the old books” (“On the Reading of Old Books” 202). Old books often contain ideas that run counter to contemporary worldviews or issues and are beneficial for the way that they often reveal the possible flaws behind current ideas. Often writers, though seemingly “as completely opposed as two sides could be were all the time secretly united—united with each other and against earlier and later ages—by a great mass of common assumptions (“On the Reading of Old Books” 202). Therefore, reading old books is preferable to new ones because not only can they help readers identify mistakes of past ages but also those same books will also enable them to better understand the problems of their own age.

            In another essay, “On Stories,” Lewis further addresses what constitutes good literature, focusing more particularly on literature as an art form. He argues that the function of art is “to present what the narrow and desperately practical perspectives of real life exclude” (“On Stories” 10). One aspect of stories that Lewis was most fond of was that, “to construct plausible and moving ‘other worlds,’ [writers and readers] must draw on the only real ‘other world’ [they] know, that of the spirit” (12). He explains further, “Good stories often introduce the marvelous or supernatural, and nothing about Story has been so often misunderstood as this” (13). This aspect of literature reveals Lewis’s earlier argument that literature can be a road both to and from heaven. Although he considers one negative possibility of escapism, the encouragement of “happiness under incompatible conditions” (14), Lewis also takes into account the potential benefit of the escape into literature: “[The] whole story, paradoxically enough, strengthens our relish for real life. This excursion into the preposterous sends us back with renewed pleasure to the actual” (15).

            Moreover, Lewis’s essay “On Three Ways of Writing for Children” explores standards for determining the quality of children’s literature. He states, “I am almost inclined to set it up as a canon that a children’s story which is enjoyed only by children is a bad children’s story” (“On Three Ways of Writing for Children” 24). Lewis touches again on the potential problem of escapism by differentiating between two types of longing: “The one is an askesis, a spiritual exercise, and the other is a disease” (30). His argument here is that, if a child “escapes” into literature, it is healthy and even beneficial, if the longing produced by entering into a fictional world is a spiritual longing. However, if the reader wishes to imaginatively live in an alternate world merely to escape the real one, then it can become destructive.

            Additionally, Lewis argues that literature should not be overtly didactic. Its primary purpose is to entertain, and a “moral” should not be incorporated at the expense of entertainment. Lewis argues that, rather than asking what moral theme or principle contemporary children need to hear, a writer ought to ask oneself what moral he or she needs to learn. Lewis advocates, “The only moral that is of any value is that which arises inevitably from the whole cast of the author’s mind,” for “what does not concern us deeply will not deeply interest our readers, whatever their age” (“On Three Ways of Writing to Children” 33). Therefore, the moral must not be something superficially placed in front of the child, but something portrayed in a real sense and driven by the true concerns of the writer.