[In "There's a certain Slant of light,"] Emily Dickinson . . . treats an irrational psychological phenomenon akin to those recorded by Wordsworth in "Strange fits of passion have I known" ("Down behind the cottage roof, At once, the bright moon dropp'd. . . . '0 mercy!' to myself I cried, 'If Lucy should be dead!"') and by Tennyson in "Mariana" ("But most she loathed the hour When the thick-moted sunbeam lay Athwart the chambers, and the day Was sloping toward his western bower.") A certain external condition of nature induces in her a certain feeling or mood. But the feeling is more complex than Wordsworth's or Mariana's.
The chief characteristic of this feeling is its painful oppressiveness. "Oppresses," "weight," "hurt," "despair," and "affliction" convey this aspect. A large component in it is probably consciousness of the fact of death, though this is probably not the whole of its content nor is this consciousness necessarily fully formulated by the mind. Yet here we see the subtle connection between the hour and the mood. For the season is winter, when the year is approaching its end. And the time is late afternoon (winter afternoons are short at best, and the light slants), when the day is failing. The suggestion of death is caught up by the weighty cathedral tunes (funeral music possibly—but hymns are also much concerned with death—"Dies Irae," etc.) and by "the distance on the look of death." The stillness of the hour ("the landscape listens, Shadows hold their breath") is also suggestive of the stillness of death.
But besides the oppressiveness of the feeling, it has a certain impressiveness too. It is weighty, solemn, majestic, like organ music. This quality is conveyed by "weight of cathedral tunes," "heavenly ," "seal" (suggesting the seal on some important official document), and "imperial." This quality of the mood may be partly caused by the stillness of the moment, by the richness of the slanting sunlight (soon to be followed by sunset), and by the image of death which it calls up.
The mood gives "heavenly" hurt. "Heavenly" suggests the immateriality of the hurt, which leaves "no scar"; the source of the sunlight—the sky; the ultimate source of both sunlight and death—God. The hurt is given internally "where the meanings are"—that is, in the soul, the psyche, or the mind-that part of one which assigns "meanings"—consciously or intuitively—to life and to phenomena like this.
"None may teach it anything"—Both the sunlight and the mood it induces are beyond human correction or alleviation; they are final and irrevocable—"sealed." There is no lifting this seal— this despair.
"When it goes, 'tis like the distance On the look of death"—The lines call up the image of the stare in the eyes of a dead man, not focused, but fixed on the distance. Also, "distance" suggests the awful distance between the living and the dead—part of the implicit content of the mood. Notice that the slanted ray and the mood are still with us here, but are also going. The final remarkable image reiterates the components of the hour and the mood—oppressiveness, solemnity, stillness, death. But it hints also at relief—hopes that there will soon be a "distance" between the poet and her experience.
From "Dickinson's 'There's a Certain Slant of Light,'" The Explicator, XI (May 1953), Item 50.