It is necessary to use to a certain extent the arbitrary subject-divisions, such as portrait, landscape, and figure painting; and to refer also to realistic painting, which tends to depict things as they are, as opposed to the academic, which recognizes the wisdom of conventionalization or idealization. But the most important distinction, for the student of contemporary tendencies, is that which concerns the term "Impressionism." This name in its original and technical sense applied to the works of the men who, instead of mixing shades, placed different colors side by side on their canvases to give the effect of the right shade at a distance. As the experiments of these artists were directed chiefly to the solution of problems of light, the term naturally was widened to include that whole division of painting which is concerned with atmospheric aspects and color harmonies rather than with subject-interest and line composition. Terms which express the same idea in general or in part, are "luminism" and "plein-air painting." Impressionism has had more effect on the current of art than has any other movement in history. Not only in the handling of light and in freshness of coloring has the whole of painting been profoundly changed, but there is a general tendency to paint the impression rather than the actuality, the harmonious effect rather than the literal fact-and these things are notably illustrated in the Exposition galleries. For the sake of the visitor who comes to the gallery with practically no knowledge of art, a word may profitably be said about critical standards. First remember that there are many qualities which may make a painting worth while: pleasing design, beautiful color, a compelling expression of emotion or thought, or a poetic suggestion of a fleeting aspect or mood. It is necessary to judge each particular work by the artist's intention, and not by untrained personal tastes. Before passing judgment learn to know the picture well. You may find that you have been attracted by something superficial. On the other hand, you may find that the seemingly less attractive picture, which has been recommended by people of trained judgment, grows more and more pleasing with riper acquaintance. Go slowly, study thoroughly what you study, and keep an open mind-for that way leads to the widest enjoyment. United States Section: Painting The United States Section consists chiefly of contemporary work, but includes a small historical section, which is to be found to the left as one enters at the main doorway. It is in this part of the exhibit that one should start. The Historical Section consists of two well-defined parts. The first contains examples of foreign schools of painting that have influenced American art. The second contains the works of American painters from the beginnings to the early Twentieth Century. The Foreign Historical Section occupies rooms 91-92 and 61-63.