a few days after the capture of Antioch, the poets in the several divisions of the successful army began to write the history of the conflict, not according to facts, but each glorifying the great men of his own group by ascribing to them great deeds such as the current poetry ascribed to legendary heroes. What could more strikingly show the absence of any notion of historic reality?
Now, if you compare our world of ideas with that of the Middle Ages, the greatest difference is that we want reality beyond everything else. We do not demand the truth because we do not know where or how to get it. We do not want rationalism, because that is only a philosophy, and it has limitations like any other philosophy. We do not demand what is natural or realistic in the philosophical sense, because that would imply a selection of things, in operation all the time, before the things were offered to us. In zoology and anthropology we want to know all forms which really exist, but we have no patience with invented and imaginary forms. In history we do not allow documents to be prepared which will serve a purpose; to us, such documents would have the character of lies. That they would be edifying or patriotic does not excuse them. Probably modern men have no harder task than the application of the historic sense to cases in those periods of history when it was not thought wrong to manufacture such documents as one's cause required.
The modern study of nature has helped to produce this way of looking at things, and the way of looking at things has made science possible. I want to have the notion of science built on this thirst for reality, and respond to it at every point. There may be knowledge of reality whose utility we do not know, but it would be overbold for any one to say that any knowledge of reality is useless.