

Above left: Danny converses with 'Tony', who is here personified by Danny's left index finger (in this screencap, we're looking at Danny's reflection in a mirror). Above right: Later in the movie, while Danny is in a state resembling hypnosis, he uses his right index finger for Tony. In his Psychology and Alchemy, Carl Jung says, "[A] leftward movement is equivalent to a movement in the direction of the unconscious, whereas a movement to the right...aims at consciousness."[a] Jung calls the unconscious the "sinister" side, and the conscious, the "correct" side. The point is that the left side represents the unconscious; and the right side represents the conscious. Therefore, Danny's left hand represents his unconscious, and his right hand, his conscious. Note that in the right-hand screencap above, Wendy is holding Danny's left arm - this is symbolic of the idea that she is here 'suppressing' Danny's expression of his unconscious.
Greek mythology's Dactyls (from Greek Δάκτυλοι "fingers") were the archaic mythical race of small phallic male beings associated with the Great Mother, whether as Cybele or Rhea. Their numbers vary, but often they were ten spirit-men so like the three Curetes, the Cabiri or the Korybantes that they were often interchangeable. The Dactyls were both ancient smiths and healing magicians. In some myths, they are in Hephaestus' employ, and they taught metalworking, mathematics, and the alphabet to humans.
When Rhea, the mother of the gods, knew her time of delivery was come, she went to the sacred cave on Mount Ida. As she squatted in labor she dug her fingers into the Earth (Gaia), which brought forth these daktyloi Idaioi (Δάκτυλοι Ἰδαῖοι "Idaean fingers"), thus often ten in number, or sometimes multiplied into a race of ten tens. Three is just as often given as their number. They are sometimes instead numbered as thirty-three.[b]
From Jung's Symbols of Transformation:[c][d] "We know that Tom Thumbs, dactyls, and Cabiri have a phallic aspect, and this is understandable enough, because they are personifications of creative forces, of which the phallus, too, is a symbol. It represents the libido, or psychic energy in its creative aspect...The same creative force which is symbolized by Tom Thumbs, etc. can also be represented by the phallus or by numerous other symbols, which delineate further aspects of the process underlying them all. Thus the creative dwarfs toil away in secret; the phallus, also working in darkness, begets a living being; and the key unlocks the mysterious forbidden door behind which some wonderful thing awaits discovery. One thinks, in this connection, of "The Mothers" in Faust:
Mephistopheles: Congratulations, before you part from me!
You know the devil, that is plain to see.
Here, take this key.
Faust: That little thing! But why?
Mephistopheles: First grasp it; it is nothing to decry.
Faust: It glows, it shines, increases in my hand!
Mephistopheles: How great its worth, you soon shall understand.
The key will smell the right place from all others:
Follow it down, it leads you to the Mothers! [e]
"Here the devil again puts into Faust's hand the marvellous tool...What he is describing here is the libido, which is not only creative and procreative, but possesses an intuitive faculty, a strange power to "smell the right place," almost as if it were a live creature with an independent life of its own (which is why it is so easily personified). It is purposive, like sexuality itself, a favourite object of comparison. The "realm of the Mothers" has not a few connections with the womb, with the matrix, which frequently symbolizes the creative aspect of the unconscious. This libido is a force of nature, good and bad at once, or morally neutral. ..."
Recall that the first time Danny tries to get into room 237, its door is locked (above left), and Danny experiences a brief vision of the twins (above right). Later in the movie, room 237's door has been opened, and there is a key hanging from its locking knob (below left). We can take room 237's door as the "forbidden door" in the above passage, its key as the "key", and Danny's and Jack's mothers as "the Mothers."


Above left: Looking into room 237. "The key will smell the right place from all others: Follow it down, it leads you to the Mothers!"[e] Above right: The very next shot is a fade to Wendy in the basement. As an aside, note that the two boilers are not quite identical (you may click on the screencap to enlarge it). This fact will come into play later when we discuss the twins.
a. Jung, C.G. The Collected Works of C.G. Jung, Vol. 12. Princeton University Press, 1968. para. 166.
b. Wikipedia 'Dactyl (mythology)'. Web, n.d. URL = http://en.wikipedia.org/wiki/Dactyl_(mythology).
c. Jung, C.G. The Collected Works of C.G. Jung, Vol. 5. Princeton University Press, 1977. pp. 124-125.
d. Italicized emphasis is in original.
e. Faust, Part II, trans. based on MacNeice, p. 177, in The Collected Works of C.G. Jung, Vol. 5.