§ 1. We have now reached the last and the most important part of our subject. We have seen in the first division of this book, how far art may be, and has been, consistent with physical or material facts. In its second division, we examined how far it may be and has been obedient to the laws of physical beauty. In this last division we have to consider the relations of art to God and man: its work in the help of human beings, and service of their Creator.

We have to inquire into the various Powers, Conditions, and Aims of mind involved in the conception or creation of pictures; in the choice of subject, and the mode and order of its history;—the choice of forms, and the modes of their arrangement.

And these phases of mind being concerned, partly with choice and arrangement of incidents, partly with choice and arrangement of forms and colours, the whole subject will fall into two main divisions, namely, expressional or spiritual invention; and material or formal invention.

They are of course connected;—all good formal invention being expressional also; but as a matter of convenience it is best to say what may be ascertained of the nature of formal invention, before attempting to illustrate the faculty in its higher field.

§ 2. First, then, of Invention Formal, otherwise and most commonly called technical composition; that is to say, the arrangement of lines, forms, or colours, so as to produce the best possible effect.