No less inevitable psychologically is the preference for works of art that treat of the problems and conditions of contemporary life. Part of this, to be sure, is expressive merely of some transient mood of the popular mind. The enthusiasm, happily passing, for the plays of Brieux or the craze for Algerian landscapes in France after the acquirement of the colony, are examples. Such preferences, being superficially motivated, correct themselves with ease, giving way to some new fashion in taste. The preference for works of art that reflect the more serious and permanent problems of contemporary society is more firmly rooted. Men inevitably seek the artistic expression of the things that deeply concern them. The problems of the reconstruction of the family, of the working classes, and of government must continue to inspire art and to determine our interest in it, until new difficulties occupy our minds. The mere passage of time, however, brings a remedy for critical injustices flowing from this source; for, when present problems are solved, the difference between living art, which expresses them, and historical art, vanishes. Then, only those works which reflect the eternal enigmas have any advantage over the others. The same process tends to eliminate the prejudice, rooted in temperament, in favor of the old and familiar in art; or, following a different bent, in favor of the new and startling. In such cases, a just estimate can be made only when the new becomes the old, and both are reduced to a common level.