"Knowledge of the past (and here we are led back to the functions of vision) may... be compared to a picture of a distant landscape, at once deceptive and exact, since its very exactitude is derived from illusion. If we could compare our past, as it has really been, fixed before us objectively, with the subjective representation which we have in memory, we would find the copy formed upon a particular system of projection: each of us is able to find his way without trouble in this system, because he has himself created it."