People 'in society' know this index by heart, they are gifted in such matters with an erudition from which they have extracted a sort of taste, of tact, so automatic in its operation that Swann, for example, without needing to draw upon his knowledge of the world, if he read in a newspaper the names of the people who had been guests at a dinner, could tell at once how fashionable the dinner had been, just as a man of letters, merely by reading a phrase, can estimate exactly the literary merit of its author.