We have hitherto been exclusively occupied with those sources of [§ 1. A partial examination only of the imagination is to be attempted.]pleasure which exist in the external creation, and which in any faithful copy of it must to a certain extent exist also.
These sources of beauty, however, are not presented by any very great work of art in a form of pure transcript. They invariably receive the reflection of the mind under whose shadow they have passed, and are modified or colored by its image.
This modification is the Work of Imagination.
As, in the course of our succeeding investigation, we shall be called upon constantly to compare sources of beauty existing in nature with the images of them presented by the human mind, it is very necessary for us shortly to review the conditions and limits of the imaginative faculty, and to ascertain by what tests we may distinguish its sane, healthy, and profitable operation, from that which is erratic, diseased, and dangerous.
It is neither desirable nor possible here to examine or illustrate in full the essence of this mighty faculty. Such an examination would require a review of the whole field of literature, and would alone demand a volume. Our present task is not to explain or exhibit full portraiture of this function of the mind in all its relations, but only to obtain some certain tests by which we may determine whether it be very imagination or no, and unmask all impersonations of it, and this chiefly with respect to art, for in literature the faculty takes a thousand forms, according to the matter it has to treat, and becomes like the princess of the Arabian tale, sword, eagle, or fire, according to the war it wages, sometimes piercing, sometimes soaring, sometimes illumining, retaining no image of itself, except its supernatural power, so that I shall content myself with tracing that particular form of it, and unveiling those imitations of it only, which are to be found, or feared, in painting, referring to other creations of mind only for illustration.
Unfortunately, the works of metaphysicians will afford us in this most interesting inquiry no aid whatsoever. They who are constantly [§ 2. The works of the metaphysicians how nugatory with respect to this faculty.]endeavoring to fathom and explain the essence of the faculties of mind, are sure in the end to lose sight of all that cannot be explained, (though it may be defined and felt,) and because, as I shall presently show, the essence of the imaginative faculty is utterly mysterious and inexplicable, and to be recognized in its results only, or in the negative results of its absence, the metaphysicians, as far as I am acquainted with their works, miss it altogether, and never reach higher than a definition of fancy by a false name.
What I understand by fancy will presently appear, not that I contend for nomenclature, but only for distinction between two mental faculties, by whatever name they be called, one the source of all that is great in the poetic arts; the other merely decorative and entertaining, but which are often confounded together, and which have so much in common as to render strict definition of either difficult.
Dugald Stewart's meagre definition may serve us for a starting point. "Imagination," he says, "includes conception or simple apprehension, [§ 3. The definition of D. Stewart, how inadequate.]which enables us to form a notion of those former objects of perception or of knowledge, out of which we are to make a selection; abstraction, which separates the selected materials from the qualities and circumstances which are connected with them in nature; and judgment or taste, which selects the materials and directs their combination. To these powers we may add that particular habit of association to which I formerly gave the name of fancy, as it is this which presents to our choice all the different materials which are subservient to the efforts of imagination, and which may therefore be considered as forming the ground-work of poetical genius."
(By fancy in this passage, we find on referring to the chapter treating of it, that nothing more is meant than the rapid occurrence of ideas of sense to the mind.)