I begin with a number of propositions, which I shall try to develop in detail:
First, that allegory and symbolism are modes of analogy, that both present one thing or concept in terms of another thing or concept, even though the ways in which they do so have been contrasted and seen as vitally different.
Secondly, that the novel is, as a literary form, generally characterized by realism, and that realism as a literary technique would appear to be opposed to analogical modes.
Thirdly, that this opposition is only apparent because all literary discourse (and in a sense all language) is analogical, in so far as it is meaningful: and that this is confirmed by critical practice.
Fourthly, that the development of the novel therefore reveals a continuing compromise in which overtly analogical modes are allowed to permeate the apparently non-analogical mode of realism in the interests of meaning.
Fifthly, that in the modern period the value of realism as a technique begins to be called into question, and consequently the point of the compromise begins to be called into question, with significant repercussions on the form of the novel.
In putting forward these ideas, particularly the last one, I have been much influenced by The Nature of Narrative (1966), by Robert Scholes and Robert Kellogg. Surveying the whole range of Western narrative literature, they suggest that the primitive oral epic was a synthesis of two antithetical types of narrative, one which they call empirical, whose primary allegiance is to the real, and the other fictional, whose primary allegiance is to the ideal.