A material thing, such as water, is seen to be clearly separate from and remotely placed from the sun etc. which are themselves material entities (with forms). There it is proper that an image of the sun should be formed. But the Self is not such a material entity (having form); and since It is all-pervasive and non-different from all, It can have no limiting adjuncts either separate or remote from It.Shankara responds:
nobody can show equality in every respect over and above some point of similarity in some way...For if such an all-round similarity exists, the very relation between the illustration and the thing illustrated will fall through.This is a crucial element of analogical thinking, but (at least to me) also extremely difficult to grasp, despite looking simple. We routinely analogize in conversation, and then, when our rough-spun comparison bumps into a problem, we usually say something like, "well, here the metaphor falls apart." Sometimes we take this in stride, but other times it leaves us oddly dissatisfied, as though something promised had failed to be delivered.
The really pertinent question is not, "what is the specific dissimilarity in this case?" but "Why do all such extended metaphors stop pertaining?" It seems to me that the reason is: because a perfect point-for-point isomorphism in every respect would not be illustration, but identity. (E.g. the map with a scale of “a mile to the mile” in Sylvie and Bruno; in Borges’ On Exactitude in Science, the Empire’s inhabitants “who were not so fond of the Study of Cartography as their Forebears had been, saw that that vast map was Useless.”)
The whole point of an analogy is the instantiating of the similar in the dissimilar.
N.b.: Ombhurbhuva seems to make a more rigorous distinction between metaphor and analogy than I am making. He promises “more anon,” so check in over there.