It is not exactly true, that this faculty can be subjected to the complete control of the will. I know of no point in metaphysics, connected, also, with an important question in rhetoric, upon which less light has been thrown, than the question, how far, and in what way the imagination can be cultivated: and by what methods brought under the control of the will. A system of useful and practical rules for this result is, as far as my reading extends, a desideratum. Dr Johnson, it is well known, believed, that a man’s muse was _sua dextra_, his own will, industry and habits, and that by a vigorous effort over himself, he could write, for example, at any time. This may be true in efforts, in which imagination is not required; but, where the vivid exercise of this faculty is requisite to excellence, it is not true. Let the most amply endowed poet suffer under mental depression, dyspepsia, a concurrence of small misfortunes and petty vexations. Let him write in a smoky apartment, and look abroad upon a leaden sky, marked with the dulness of winter, without its storms and congenial horrors. He may repair to his rules. He may apply the whip and spur, and invoke the nimble fancies from the vasty deep, and the muses from their hill, but they will not answer, nor come at his bidding. The imagination may be cultivated to a certain extent; and brought by rules and intense concentration of mind, in a certain degree, under the control of the will. Those, who would nurture it, ought intensely to study those rules. But, after all, to be able to exercise it in high measures of vivacity, is an endowment, in the bestowment of which nature has been more capricious than in almost any other. Even when possessed in copious measures, its province lies so intermediate between corporeal and mental influence, between the prevalent temperament of the period of its action, and the concurrence of external circumstances beyond our control, that we can easily see, why the wise ancients, who thought more justly upon these subjects, and more profoundly than the moderns seem to be willing to apprehend, attributed the successful efforts of the muses to a superior and celestial influence. He, who pushes the theory of our control over this faculty beyond truth, adopts an error, nearly if not quite as dangerous, as he, who holds, that we have no control over it at all.