On the imagination, or esemplastic power
O Adam, One Almighty is, from whom All things proceed, and up to him return, If not deprav'd from good, created all Such to perfection, one first matter all, Endued with various forms, various degrees Of substance, and, in things that live, of life; But more refin'd, more spiritous and pure, As nearer to him plac'd, or nearer tending, Each in their several active spheres assigu'd, Till body up to spirit work, in bounds Proportion'd to each kind. So from the root Springs lighter the green stalk, from thence the leaves More aery: last the bright consummate flower Spirits odorous breathes: flowers and their fruit, Man's nourishment, by gradual scale sublim'd, To vital spirits aspire: to animal: To intellectual!--give both life and sense, Fancy and understanding; whence the soul REASON receives, and reason is her being, Discursive or intuitive. 
"Sane dicerentur si res corporales nil nisi materiale continerent, verissime in fluxu consistere, neque habere substantiale quicquam, quemadmodum et Platonici olim recte agnovere."
"Hinc igitur, praeter pure mathematica et phantasiae subjecta, collegi quaedam metaphysica solaque mente perceptibilia, esse admittenda et massae materiali principium quoddam superius et, ut sic dicam, formale addendum: quandoquidem omnes veritates rerum corporearum ex solis axiomatibus logisticis et geometricis, nempe de magno et parvo, toto et parte, figura et situ, colligi non possint; sed alia de causa et effectu, actioneque et passione, accedere debeant, quibus ordinis rerum rationes salventur. Id principium rerum, an entelecheian an vim appellemus, non refert, modo meminerimus, per solam Virium notionem intelligibiliter explicari." 
Sebomai noeron Kruphian taxin Chorei TI MESON Ou katachuthen. 
Des Cartes, speaking as a naturalist, and in imitation of Archimedes, said, give me matter and motion and I will construct you the universe. We must of course understand him to have meant; I will render the construction of the universe intelligible. In the same sense the transcendental philosopher says; grant me a nature having two contrary forces, the one of which tends to expand infinitely, while the other strives to apprehend or find itself in this infinity, and I will cause the world of intelllgences with the whole system of their representations to rise up before you. Every other science presupposes intelligence as already existing and complete: the philosopher contemplates it in its growth, and as it were represents its history to the mind from its birth to its maturity.
The venerable sage of Koenigsberg has preceded the march of this master-thought as an effective pioneer in his essay on the introduction of negative quantities into philosophy, published 1763. In this he has shown, that instead of assailing the science of mathematics by metaphysics, as Berkeley did in his ANALYST, or of sophisticating it, as Wolf did, by the vain attempt of deducing the first principles of geometry from supposed deeper grounds of ontology, it behoved the metaphysician rather to examine whether the only province of knowledge, which man has succeeded in erecting into a pure science, might not furnish materials, or at least hints, for establishing and pacifying the unsettled, warring, and embroiled domain of philosophy. An imitation of the mathematical method had indeed been attempted with no better success than attended the essay of David to wear the armour of Saul. Another use however is possible and of far greater promise, namely, the actual application of the positions which had so wonderfully enlarged the discoveries of geometry, mutatis mutandis, to philosophical subjects. Kant having briefly illustrated the utility of such an attempt in the questions of space, motion, and infinitely small quantities, as employed by the mathematician, proceeds to the idea of negative quantities and the transfer of them to metaphysical investigation. Opposites, he well observes, are of two kinds, either logical, that is, such as are absolutely incompatible; or real, without being contradictory. The former he denominates Nihil negativum irrepraesentabile, the connection of which produces nonsense. A body in motion is something-- Aliquid cogitabile; but a body, at one and the same time in motion and not in motion, is nothing, or, at most, air articulated into nonsense. But a motory force of a body in one direction, and an equal force of the same body in an opposite direction is not incompatible, and the result, namely, rest, is real and representable. For the purposes of mathematical calculus it is indifferent which force we term negative, and which positive, and consequently we appropriate the latter to that, which happens to be the principal object in our thoughts. Thus if a man's capital be ten and his debts eight, the subtraction will be the same, whether we call the capital negative debt, or the debt negative capital. But in as much as the latter stands practically in reference to the former, we of course represent the sum as 10-8. It is equally clear that two equal forces acting in opposite directions, both being finite and each distinguished from the other by its direction only, must neutralize or reduce each other to inaction. Now the transcendental philosophy demands; first, that two forces should be conceived which counteract each other by their essential nature; not only not in consequence of the accidental direction of each, but as prior to all direction, nay, as the primary forces from which the conditions of all possible directions are derivative and deducible: secondly, that these forces should be assumed to be both alike infinite, both alike indestructible. The problem will then be to discover the result or product of two such forces, as distinguished from the result of those forces which are finite, and derive their difference solely from the circumstance of their direction. When we have formed a scheme or outline of these two different kinds of force, and of their different results, by the process of discursive reasoning, it will then remain for us to elevate the thesis from notional to actual, by contemplating intuitively this one power with its two inherent indestructible yet counteracting forces, and the results or generations to which their inter-penetration gives existence, in the living principle and in the process of our own self- consciousness. By what instrument this is possible the solution itself will discover, at the same time that it will reveal to and for whom it is possible. Non omnia possumus omnes. There is a philosophic no less than a poetic genius, which is differenced from the highest perfection of talent, not by degree but by kind.
The counteraction then of the two assumed forces does not depend on their meeting from opposite directions; the power which acts in them is indestructible; it is therefore inexhaustibly re-ebullient; and as something must be the result of these two forces, both alike infinite, and both alike indestructible; and as rest or neutralization cannot be this result; no other conception is possible, but that the product must be a tertium aliquid, or finite generation. Consequently this conception is necessary. Now this tertium aliquid can be no other than an inter-penetration of the counteracting powers, partaking of both.
* * * * * * *
Thus far had the work been transcribed for the press, when I received the following letter from a friend, whose practical judgment I have had ample reason to estimate and revere, and whose taste and sensibility preclude all the excuses which my self-love might possibly have prompted me to set up in plea against the decision of advisers of equal good sense, but with less tact and feeling.
"You ask my opinion concerning your Chapter on the Imagination, both as to the impressions it made on myself, and as to those which I think it will make on the Public, i.e. that part of the public, who, from the title of the work and from its forming a sort of introduction to a volume of poems, are likely to constitute the great majority of your readers.
"As to myself, and stating in the first place the effect on my understanding, your opinions and method of argument were not only so new to me, but so directly the reverse of all I had ever been accustomed to consider as truth, that even if I had comprehended your premises sufficiently to have admitted them, and had seen the necessity of your conclusions, I should still have been in that state of mind, which in your note in Chap. IV you have so ingeniously evolved, as the antithesis to that in which a man is, when he makes a bull. In your own words, I should have felt as if I had been standing on my head.
"The effect on my feelings, on the other hand, I cannot better represent, than by supposing myself to have known only our light airy modern chapels of ease, and then for the first time to have been placed, and left alone, in one of our largest Gothic cathedrals in a gusty moonlight night of autumn. 'Now in glimmer, and now in gloom;' often in palpable darkness not without a chilly sensation of terror; then suddenly emerging into broad yet visionary lights with coloured shadows of fantastic shapes, yet all decked with holy insignia and mystic symbols; and ever and anon coming out full upon pictures and stone-work images of great men, with whose names I was familiar, but which looked upon me with countenances and an expression, the most dissimilar to all I had been in the habit of connecting with those names. Those whom I had been taught to venerate as almost super-human in magnitude of intellect, I found perched in little fret-work niches, as grotesque dwarfs; while the grotesques, in my hitherto belief, stood guarding the high altar with all the characters of apotheosis. In short, what I had supposed substances were thinned away into shadows, while everywhere shadows were deepened into substances:
If substance might be call'd that shadow seem'd, For each seem'd either!
"Yet after all, I could not but repeat the lines which you had quoted from a MS. poem of your own in the FRIEND, and applied to a work of Mr. Wordsworth's though with a few of the words altered:
------An Orphic tale indeed, A tale obscure of high and passionate thoughts To a strange music chanted!
"Be assured, however, that I look forward anxiously to your great book on the CONSTRUCTIVE PHILOSOPHY, which you have promised and announced: and that I will do my best to understand it. Only I will not promise to descend into the dark cave of Trophonius with you, there to rub my own eyes, in order to make the sparks and figured flashes, which I am required to see.
"So much for myself. But as for the Public I do not hesitate a moment in advising and urging you to withdraw the Chapter from the present work, and to reserve it for your announced treatises on the Logos or communicative intellect in Man and Deity. First, because imperfectly as I understand the present Chapter, I see clearly that you have done too much, and yet not enough. You have been obliged to omit so many links, from the necessity of compression, that what remains, looks (if I may recur to my former illustration) like the fragments of the winding steps of an old ruined tower. Secondly, a still stronger argument (at least one that I am sure will be more forcible with you) is, that your readers will have both right and reason to complain of you. This Chapter, which cannot, when it is printed, amount to so little as an hundred pages, will of necessity greatly increase the expense of the work; and every reader who, like myself, is neither prepared nor perhaps calculated for the study of so abstruse a subject so abstrusely treated, will, as I have before hinted, be almost entitled to accuse you of a sort of imposition on him. For who, he might truly observe, could from your title-page, to wit, "My Literary Life and Opinions," published too as introductory to a volume of miscellaneous poems, have anticipated, or even conjectured, a long treatise on Ideal Realism which holds the same relation in abstruseness to Plotinus, as Plotinus does to Plato. It will be well, if already you have not too much of metaphysical disquisition in your work, though as the larger part of the disquisition is historical, it will doubtless be both interesting and instructive to many to whose unprepared minds your speculations on the esemplastic power would be utterly unintelligible. Be assured, if you do publish this Chapter in the present work, you will be reminded of Bishop Berkeley's Siris, announced as an Essay on Tar-water, which beginning with Tar ends with the Trinity, the omne scibile forming the interspace. I say in the present work. In that greater work to which you have devoted so many years, and study so intense and various, it will be in its proper place. Your prospectus will have described and announced both its contents and their nature; and if any persons purchase it, who feel no interest in the subjects of which it treats, they will have themselves only to blame.
"I could add to these arguments one derived from pecuniary motives, and particularly from the probable effects on the sale of your present publication; but they would weigh little with you compared with the preceding. Besides, I have long observed, that arguments drawn from your own personal interests more often act on you as narcotics than as stimulants, and that in money concerns you have some small portion of pig-nature in your moral idiosyncrasy, and, like these amiable creatures, must occasionally be pulled backward from the boat in order to make you enter it. All success attend you, for if hard thinking and hard reading are merits, you have deserved it.
Your affectionate, etc."
In consequence of this very judicious letter, which produced complete conviction on my mind, I shall content myself for the present with stating the main result of the chapter, which I have reserved for that future publication, a detailed prospectus of which the reader will find at the close of the second volume.
The Imagination then I consider either as primary, or secondary. The primary Imagination I hold to be the living power and prime agent of all human perception, and as a repetition in the finite mind of the eternal act of creation in the infinite I AM. The secondary Imagination I consider as an echo of the former, co-existing with the conscious will, yet still as identical with the primary in the kind of its agency, and differing only in degree, and in the mode of its operation. It dissolves, diffuses, dissipates, in order to recreate: or where this process is rendered impossible, yet still at all events it struggles to idealize and to unify. It is essentially vital, even as all objects (as objects) are essentially fixed and dead.
FANCY, on the contrary, has no other counters to play with, but fixities and definites. The fancy is indeed no other than a mode of memory emancipated from the order of time and space; while it is blended with, and modified by that empirical phaenomenon of the will, which we express by the word Choice. But equally with the ordinary memory the Fancy must receive all its materials ready made from the law of association.
 Par. Lost. Book V. I. 469.
 Leibnitz. Op. T. II. P. II. p. 53.--T. III. p. 321.
 Synesii Episcop. Hymn. III. I. 231