misdirected effort has been wasted on this object, all enjoyment of the medium being subordinated to a meretricious attempt to deceive the eye.  And I believe a popular idea of the art of painting is that it exists chiefly to produce this deception.  No vital expression of nature can be achieved without the aid of the particular vitality possessed by the medium with which one is working.  If this is lost sight of and the eye is tricked into thinking that it is looking at real nature, it is not a fine picture.  Art is not a substitute for nature, but an expression of feeling produced in the consciousness of the artist, and intimately associated with the material through which it is expressed in his work—­inspired, it may be, in the first instance, by something seen, and expressed by him in painted symbols as true to nature as he can make them while keeping in tune to the emotional idea that prompted the work; but never regarded by the fine artist as anything but painted symbols nevertheless.  Never for one moment does he intend you to forget that it is a painted picture you are looking at, however naturalistic the treatment his theme may demand.

In the earlier history of art it was not so necessary to insist on the limitations imposed by different mediums.  With their more limited knowledge of the phenomena of vision, the early masters had not the same opportunities of going astray in this respect.  But now that the whole field of vision has been discovered, and that the subtlest effects of light and atmosphere are capable of being represented, it has become necessary to decide how far complete accuracy of representation will help the particular impression you may intend your picture or drawing to create.  The danger is that in producing a complete illusion of representation, the particular vitality of your medium, with all the expressive power it is capable of yielding, may be lost.

Perhaps the chief difference between the great masters of the past and many modern painters is the neglect of this principle. #They represented nature in terms of whatever medium they worked in, and never overstepped this limitation#.  Modern artists, particularly in the nineteenth century, often attempted to #copy nature#, the medium being subordinated to the attempt to make it look like the real thing.  In the same way, the drawings of the great masters were drawings.  They did not attempt anything with a point that a point was not capable of expressing.  The drawings of many modern artists are full of attempts to express tone and colour effects, things entirely outside the true province of drawing.  The small but infinitely important part of nature that pure drawing is capable of conveying has been neglected, and line work, until recently, went out of fashion in our schools.