gaslight

What does it mean to read a text in different ways?  Will Self said recently that his work can be read differently much as can Conrad's. How does a text come to be capable of this?  Consider the example of Benjamin's use of gaslight: developing his theory of modernity he draws on R. L. Stevenson's depiction of gaslight in Victorian Edinburgh; R.L.S, he says writes the epitaph of gaslight after which it is electric light that illuminates the life of the gloomy city dweller. R.L.S. did not intend a use of this kind but what he says has to resonate deeply enough for Benjamin to exploit; the earlier intellectual resource has to be sufficient as in the form of a template. Consider further, Munoz who made a series of drawings on the theme of Conrad's Outpost of progress. Are these examples simply 'variations on a theme by...'?  Perhaps there needs to be an equality of imagination between the former and the later. A reader in the far future will need to weigh Heart of Darkness with Liver: A Fictional Organ with a Surface Anatomy of Four Lobes.A final thought: does Achebe's charge that Conrad is a racist apply equally to Munoz?