Some think that The Crystal Cabinet is a veiled reference to an early or illicit sexual experience. But the sexual implications may be metaphors for the same kind of transcendent intuitive experience which C.S. Lewis evoked in his allegory Pilgrim's Regress or his autobiography Surprised by Joy.
Lewis develops the idea that man is given glimpses of a world beyond ordinary experience that keeps him seeking for the unknown object which can satisfy his desire.
In the preface to Pilgrim's Regress (1943 Edition), Lewis makes these statements about the desire he speaks of as joy:
"For this sweet Desire cuts across our ordinary distinction between wanting and having. To have it is, by definition, a want: to want it, we find is to have it."
"I know them [various objects of this Desire] to be wrong not by intelligence but by experience,"
"It appeared to me therefore that if a man diligently followed this desire, pursuing the false objects until their falsity appeared and then resolutely abandoning them, he must come out at last into the clear knowledge that the human soul was made to enjoy some object that is never fully given - in our present mode of spatio/temporal experience."
Lewis describes the longing for an unknown world or for an experience of which he had a glimpse unbidden. He wants to repeat the original feeling which came with the vision. He is disillusioned as a series of objects give temporary satisfaction but lead him to search further for the source.
Read from Book Two, Chapter V, Leah for Rachel, Page 8 of The Pilgrim's Regress: An Allegorical Apology for Christianity Reason and Romanticism:
"It seemed to him that a mist which hung at the far end of the wood had parted for a moment, and through the rift he had seen a clam sea, and in the sea an island, where the smooth turf sloped down unbroken to the bay, and out of the thickets peeped the pale, small-breasted Oreads, wise like gods, unconscious of themselves like beasts, and tall enchanters, bearded to their feet, sat in green chairs among the forests. But even while he pictured these things he knew, with one part of his mind, that they were not like the things he had seen - nay, that what had befallen him was not seeing at all."
"He shut his eyes and set his teeth again and made a picture of the Island in his mind: but he could not keep his attention on the picture because he wanted all the time to watch some other part of his mind to see if the feeling were beginning . But no feeling began: and then, just as he was opening his eyes he heard a voice speaking to him. It was quite close at hand, and very sweet, and not at all like the old voice of the wood. When he looked round he saw what he had never expected, yet was not surprised. There on the grass beside him sat a laughing brown girl of about his own age, and she had no clothes on.
'It was me you wanted,' said the brown girl. 'I am better than your silly islands.'
And John caught her, all in haste, and committed fornication with her in the wood."
In his autobiography Surprised by Joy C. S. Lewis covers his youth leading up to his conversion to Christ. Lewis identifies the awareness of Joy as the intimation of the Spirit which he first perceived as a young child but to which he could give no name:
"But soon (I cannot say how soon) nature ceased to be a mere reminder of the books, became herself the medium of the real joy. I do not say she ceased to be a reminder. All Joy reminds. It is a never a possession, always a desire for something longer ago or further away or still 'about to be.'"
"And finally, the change I had undergone introduces a new difficulty in the writing of this present book. From the first moment in the schoolroom at Chartres my secret, imaginative life began to be so important and so distinctive from my outer life that I almost have to tell two separate stories. The two lives do not influence each other at all. Where there are hungry wastes, starving for Joy, in the one, the other may be full of cheerful bustle and success; or again, where the outer life is miserable, the other may be brimming over with ecstasy. By the imaginative life I here mean only my life as concerned with Joy - including in the outer life much that would ordinarily be called imagination, as, for example, much of my reading, and all my erotic or ambitious fantasies; for these are self-regarding."
"...I concluded that it was a mood or state within myself which might turn up in any context. To 'get it again' became my constant endeavor; while reading every poem, hearing every piece of music, going for every walk, I stood anxious sentinel at my own mind to watch whether the blessed moment was beginning and to retain it if it did. Because I was still young the whole world of beauty was opening before me, my own officious obstructions were often swept aside and, startled into self-forgetfulness, I tasted Joy again. But far more often I frightened it away by my greedy impatience to snare it, and, even when it came, instantly destroy it by introspection, and at all times vulgarized it by my false assumption about its nature.
One thing, however, I learned, which has since saved me from many confusions of mind. I came to know by experience that it was not a disguise for sexual desire. Those who think that if adolescents were all provided with suitable mistresses we should soon hear no more of 'immortal longings' are certainly wrong...Joy is not a substitute for sex; sex is often a substitute for Joy. I sometimes wonder if all pleasures are not substitutes for Joy."
In reading these passages one may see numerous parallels with Blake's concepts. First, what led me to look at C. S. Lewis' writings is the inviting nature of the maiden in the Crystal Cabinet. Then we notice the introduction of the maiden gives an enhanced ability to see, and we observe the fleeting nature of the experience. The disappointment when one cannot hold onto the experience is present in the Crystal Cabinet and in encountering joy. Finding that Lewis describes another aspect of Blake's system as well is a bonus: Lewis and Blake describe the process of following the pursuit of the mistaken object or behavior until the error is apparent. Lewis, too, uses the words 'imaginative life' echoing Blake's understanding of imagination as the true life of man.
Lewis had much more to say about the intuitive experience he called Joy than Blake's few stanzas of poetry state. But Blake's poem is just one link in a chain which one may follow throughout his work.
Picture from Blake's Water-Colours for the Poems of Thomas Gray