All the most subtle truths of literature are to be found in legend. There is no better test of the truth of serious fiction than the simple truths to be found in a fairy tale or an old ballad. Now, in the whole of folk-lore there is no such thing as free love. There is such a thing as false love. There is also another thing, which the old ballads always talk of as true love. But the story always turns on the keeping of a bond or the breaking of it; and this quite apart from orthodox morality in the matter of the marriage bond. The love may be in the strict sense sinful, but it is never anarchical. There was quite as little freedom for Lancelot as for Arthur; quite as little mere philandering in the philosophy of Tristram as in the philosophy of Galahad. It may have been unlawful love, but it certainly was not lawless love. In the old ballads there is the triumph of true love, as in “The Bailiff’s Daughter of Islington”; or the tragedy of true love, as in “Helen of Kirkconnel Lea”; or the tragedy of false love, as in the ballad of “Oh waly, waly up the bank.” But there is neither triumph nor tragedy in the idea of _avowedly_ transient love; and no literature will ever be made out of it, except the very lightest literature of satire. And even the satire must be a satire on fickleness, and therefore involve an indirect ideal of fidelity. But you cannot make any enduring literature out of love _conscious_ that it will not endure. Even if this mutability were working as morality, it would still be unworkable as art. The decadents used to say that things like the marriage vow might be very convenient for commonplace public purposes, but had no place in the world of beauty and imagination. The truth is exactly the other way. The truth is that if marriage had not existed it would have been necessary for artists to invent it. The truth is that if constancy had never been needed as a social requirement, it would still have been created out of cloud and air as a poetical requirement. If ever monogamy is abandoned in practice, it will linger in legend and in literature. When society is haunted by the butterfly flitting from flower to flower, poetry will still be describing the desire of the moth for the star; and it will be a fixed star. Literature must always revolve round loyalties; for a rudimentary psychological reason, which is simply the nature of narrative. You cannot tell a _story_ without the idea of pursuing a purpose and sticking to a point. You cannot tell a story without the idea of the Quest, the idea of the Vow; even if it be only the idea of the Wager.