And quite as difficult is it to create or to apprehend by description images of mental facts, of which we have no direct experience. I may indeed, as I have already said, bring home to my mind so complex a fact as an historical character, by composition out of my experiences about character generally; Tiberius, James the First, Louis the Eleventh, or Napoleon; but who is able to infuse into me, or how shall I imbibe, a sense of the peculiarities of the style of Cicero or Virgil, if I have not read their writings? or how shall I gain a shadow of a perception of the wit or the grace ascribed to the conversation of the French salons, being myself an untravelled John Bull? And so again, as regards the affections and passions of our nature, they are _sui generis_ respectively, and incommensurable, and must be severally experienced in order to be apprehended really. I can understand the _rabbia_ of a native of Southern Europe, if I am of a passionate temper myself; and the taste for speculation or betting found in great traders or on the turf, if I am fond of enterprise or games of chance; but on the other hand, not all the possible descriptions of headlong love will make me comprehend the _delirium_, if I have never had a fit of it; nor will ever so many sermons about the inward satisfaction of strict conscientiousness create in my mind the image of a virtuous action and its attendant sentiments, if I have been brought up to lie, thieve and indulge my appetites. Thus we meet with men of the world who cannot enter into the very idea of devotion, and think, for instance, that, from the nature of the case, a life of religious seclusion must be either one of unutterable dreariness or abandoned sensuality, because they know of no exercise of the affections but what is merely human; and with others again, who, living in the home of their own selfishness, ridicule as something fanatical and pitiable the self-sacrifices of generous high-mindedness and chivalrous honour. They cannot create images of these things, any more than children can on the contrary of vice, when they ask whereabouts and who the bad men are; for they have no personal memories, and have to content themselves with notions drawn from books or from what others tell them. So much on the apprehension of things and on the real sense in our use of language; now let us pass on to the notional sense.