But there are two types of universality, one by exclusion, the other by inclusion. Communists like Tolstoy demand that art express only those feelings that are already common, the religious and moral; they would exclude all values that have not become those of the race. But this is to diminish the importance of art; for it is art's privilege to make feelings common by providing a medium through which they can be communicated rather than merely to express them after they have become common. Understanding is more valuable when it encompasses the things that tend to separate and distinguish men than when it is limited to the things that unite them. There is nothing so bizarre that art may not express it, provided it be communicable. The life of the imagination, which is the life of art, is, moreover, the only life that we can have in common. Sharing life can never mean anything else than possessing the life of one another sympathetically. Actually to lead another's life would involve possessing his body, occupying his position, doing his work, and so destroying him. But through the sympathetic imagination we can penetrate his life and leave him in possession. To do this thoroughly is possible, however, only with the life of a very few people, with intimates and friends. With the mass, we can share only ideal things like religion or patriotism, but these also are matters of imagination. Now art enlarges the scope of this common life by creating a new imaginary world to which we can all belong, where action, enjoyment, and experience do not involve competition or depend on possession and mastery. Finally, the intuitions that art provides are relatively permanent. Art not only extends life and enables us to share it, but also preserves it. Existence has a leak in it, as Plato said; experience flows in and then flows out forever. The individual passes from one act to another, from one phase of life to another, childhood, then youth, then old age. So the race; one generation follows another, and each type of civilization displaces a predecessor. Against this flux, our belief in progress comforts us; maturity is better than youth, we think, and each generation happier and more spiritual than the last. Yet the consolations of progress are partial. For even if we always do go on to something better in the future, the past had its unique value, and that is lost ineluctably. The present doubtless repeats much of the form of the past--the essential aspects of human nature remain the same; but the subtle, distinctive bloom of each stage of personal life, and of each period of the world's history, is transient. We cannot again become children, nor can we possess again the strenuous freedom of the Renaissance or the unclouded integrity of personality of the Greeks.