Only the adventurous can understand the greatness of the past. In its day, the literature of the past was an adventure. Aischylus, Sophocles, Euripides were adventurers in the world of thought. To read their plays without any sense of new ways of understanding the world and of savouring its emotions is to miss the vividness which constitutes their whole value. But adventures are to the adventurous. Thus a passive knowledge of the past loses the whole value of its message.