For many years, one of the projects on a back-burner in my mind has been the writing of a novel, A Paradox of Shadows, in which the principal character is attempting to reconstruct or to otherwise recover an ancient work, the title of which might have been
περὶ τοῦ ἀτόπου τοῦ τῶν σκιῶν, or
De [Anomalia de] Obumbratio, or perhaps something else.
Everything about the work is a matter of doubt or of conjecture, including its author and the era and language in which it were originally composed; even that there ever were such a work is uncertain. Its existence is primarily inferred from how parts of it seem to be esoterically embedded in other works; sometimes these passages can be made to fit together like bits of a jigsaw, but different ways of fitting are possible, especially allowing for lacunæ, interpolations, and unintended errors in translation or in transcription. In ancient art and literature are found what may be other references to the work, but these apparent references are subject to alternate interpretation, especially as many of them would be quite oblique if indeed they refer to the work. The search is largely a matter of poring over old manuscripts and documents.
No rational person would look at any one piece of evidence known to the main character and conclude that the work must have existed or just probably existed. Few would take the evidence as jointly establishing such a probability. There is both too much and too little information, so that bold intellectual leaps must be made in chaos or in darkness. A searcher may encounter unscalable cliffs or unbridgable chasms; and, if forced to stop at any point, one is likely to look pathetic. But the evidence, taken jointly, associates a relative plausibility of recovery with each of various possibilities as to the nature of the work. In that context, the possible profundity is enough to drive the search by the principal character, even with likely failure.