Eco, being a semiotician, is hailed by semiotics students who like to use his novel to explain their discipline. The techniques of telling stories within stories, partial fictionalization, and purposeful linguistic ambiguity are all apparent. The solution to the central murder mystery hinges on the contents of Aristotle's book on Comedy, of which no copy survives; Eco nevertheless plausibly describes it and has his characters react to it appropriately in their medieval setting – which, though realistically described, is partly based on Eco's scholarly guesses and imagination. It is virtually impossible to untangle fact and history from fiction and conjecture in the novel. Through the motif of this lost and possibly suppressed book which might have aestheticized the farcical, the unheroic and the skeptical, Eco also makes an ironically slanted plea for tolerance and against dogmatic or self-sufficient metaphysical truths – an angle which reaches the surface in the final chapters.
Umberto Eco is a significant postmodernist theorist and The Name of the Rose is a postmodern novel. The quote in the novel, "books always speak of other books, and every story tells a story that has already been told," refers to a postmodern idea that all texts perpetually refer to other texts, rather than external reality. In true postmodern style, the novel ends with uncertainty: "very little is discovered and the detective is defeated" (postscript). William of Baskerville solves the mystery in part by mistake; he thought there was a pattern but it in fact, numerous "patterns" were involved and combined with haphazard mistakes by the killers. William concludes in fatigue that there "was no pattern". Thus Eco turns the modernist quest for finality, certainty and meaning on its head, leaving the overall plot partly the result of accident and arguably without meaning. Even the novel's title alludes to the possibility of many meanings or of nebulous meaning; Eco saying in the Postscript he chose the title "because the rose is a symbolic figure so rich in meanings that by now it hardly has any meaning left".