The usual way of describing the process by which a slight sketch from nature is converted into a finished drawing is to say that the artist copied his sketch as far as it went and then relied upon his memory for the further elaboration that was required. An artist’s memory is assumed to consist of images of the scenes he has witnessed, which he has some mysterious power of storing somewhere in his mind, something like, I suppose, the undeveloped exposures in a Kodak. According to this theory we should have to assume that the particular sight of the sun rising behind Norham Towers which had greeted Turner on the morning he hurried from Berwick to Kelso had been treasured up in the inner recesses of his consciousness, and then some months afterwards, when the appropriate moment came, he had only to select this particular image from among the millions of other images in the same mysterious storehouse, to develop it and copy it on to his canvas. I need hardly add that this desperate theory is quite fanciful and absurd, and in flat contradiction to the teachings of modern psychology. A description that would not be open to such objections would run something like this: When we are dealing with the processes of artistic creation we have to assume an intelligent human agent, and analogies drawn from purely mechanical sources can only mislead us. We must not assume that an artist’s senses and intellect work like the mechanism of a camera, or in any other abnormal way, unless we have some strong evidence to support us. And we must also remember that a visual image is a useful abstraction in psychology, but in the conscious life of an intelligent human being it is merely an element within the ordinary life of thought and feeling. Let us therefore assume that Turner not only made no effort to retain the exact visual impression of the scene in question, but that he did not even attempt to separate this impression from the general whole of thought and feeling in which it was experienced. The particular matter of sense-perception would then become incorporated in the general idea or the object--in the ordinary way in which sense qualities are preserved in ideas. When Turner therefore sat down to make his picture, what he would have prominently and clearly before his mind would be a general idea of Norham Castle as a ruined border fortress, a scene of many a bloody fray and of much bygone splendour and suffering. In short, his idea would be what the art-criticism of the Henley type used to describe contemptuously as “literary”; that is, it was steeped in the colours of the historical imagination, and was practically the same as that which a man like Sir Walter Scott or any cultivated person of the present time would associate with the same object. Instead, therefore, of having a single image before his mind which he had merely to copy, Turner started with a complex idea, which might, indeed, have been expressed more or less