I think that friendly artistic gatherings are not only very enjoyable but very useful. A man who systematically keeps aloof from all his colleagues, generally deteriorates; but the object of these gatherings should be the interchange of ideas, and not the production of crude, hasty sketches.
An historical or figure painter ought, in addition to his knowledge of the human frame, to study the connection between mind and expression, and to steer a middle course between the facial monotony of Giotto, Orcagna, and the early masters, and the grotesque grimacing of the Mantegna school. The works of Lebrun and Lavater on facial expression are ridiculous and useless; indeed, nature is the only book we ought to consult if we wish truly to depict the effects of anger, fear, love, and all the other human passions. Instead, therefore, of extending my observations in this direction, I will return to the proper object of my lecture and give you a few more hints about the arrangement of a picture.
Many artists, in designing historical or what I call historical incident pictures, prefer oblique to parallel perspective. There are reasons for and against this practice, and I am far from condemning oblique perspective in every case; but I think that, speaking generally, the simpler method is preferable. Oblique perspective has the merit of being more picturesque and less formal; but, on the other hand, it is less easily understood, and although perfectly correct, often gives a figure-picture a lop-sided look.
In every picture, the horizon should be either above or below the centre of the canvas, and not bisect it into two equal portions. This is evident enough in landscape-painting, but the reasons for observing this rule in figure-pictures (particularly in those where the scene is the interior of a room, and no horizon is visible) are not so obvious.
Practically, however, it will almost always be found desirable to place the horizon considerably below the centre.
Similarly the point of sight (which in parallel perspective would, of course, coincide with the vanishing point) should not be in the centre of the picture, unless, indeed, the subject happens to be one of the severest kind.
It should be nearest to that side of the picture from which the light comes.
Suppose the figures in a picture to be lighted from the left of the spectator, and that the picture is hung in its proper light. You would not stand exactly opposite the centre of the canvas to get a good view. You would naturally place yourself a little on the side whence the light comes. Hence it is desirable that the point of sight should also be on that side.
Where the perspective is parallel, the eye is not at all shocked when the point of sight is fairly out of the picture.
Indeed, in pictures which represent a small area, the effect is more agreeable when the lines converge toward a point outside.