The hypothesis that significant form is the essential quality in a work of art has at least one merit denied to many more famous and more striking--it does help to explain things. We are all familiar with pictures that interest us and excite our admiration, but do not move us as works of art. To this class belongs what I call "Descriptive Painting"--that is, painting in which forms are used not as objects of emotion, but as means of suggesting emotion or conveying information. Portraits of psychological and historical value, topographical works, pictures that tell stories and suggest situations, illustrations of all sorts, belong to this class. That we all recognise the distinction is clear, for who has not said that such and such a drawing was excellent as illustration, but as a work of art worthless? Of course many descriptive pictures possess, amongst other qualities, formal significance, and are therefore works of art: but many more do not. They interest us; they may move us too in a hundred different ways, but they do not move us aesthetically. According to my hypothesis they are not works of art. They leave untouched our aesthetic emotions because it is not their forms but the ideas or information suggested or conveyed by their forms that affect us. Few pictures are better known or liked than Frith's "Paddington Station"; certainly I should be the last to grudge it its popularity. Many a weary forty minutes have I whiled away disentangling its fascinating incidents and forging for each an imaginary past and an improbable future. But certain though it is that Frith's masterpiece, or engravings of it, have provided thousands with half-hours of curious and fanciful pleasure, it is not less certain that no one has experienced before it one half-second of aesthetic rapture--and this although the picture contains several pretty passages of colour, and is by no means badly painted. "Paddington Station" is not a work of art; it is an interesting and amusing document. In it line and colour are used to recount anecdotes, suggest ideas, and indicate the manners and customs of an age: they are not used to provoke aesthetic emotion. Forms and the relations of forms were for Frith not objects of emotion, but means of suggesting emotion and conveying ideas.