Had I not seen the sun
I could have borne the shade;
But light a newer wilderness
My wilderness has made.
This poem demonstrates Dickinson’s telegraphic and powerfully explosive poetics with a profound single-sentence. In a poem this short, a repeated word warrants attention; “wilderness” is a word that we are encouraged to ponder. Though the speaker reveals that light has entered her wilderness and has changed it, the wilderness of her life and world remains a wilderness. Something in her awareness has shifted, and yet her world is still unknowable and wild, or perhaps even more so now.
We are not given any clues as to what the “light” is that has entered the speaker’s consciousness; and exactly what change has occurred is also unknown. Dickinson, consciously or unconsciously, evokes Plato’s notion of the cave in which the inhabitants of the cave -- with their backs to the open door --are only a head-turn away from discovering an outside world. The other cave-dwellers who have seen this outside world cannot communicate what they have seen because their friends who have never turned around have no possible way of understanding.
We can also see 116 as a love poem in which the speaker tells of a new love that has entered her life and who she can no longer imagine living without. Perhaps if she had not met this person of "light", she could have easily imagined living without him or her; yet, now that she has known this love, she can no longer bear the “shade” of their absence.
The sun could also be a reference to an immortal life force, with the wilderness as a stand in for the earth and the mortal world. Knowledge of an afterlife or a so-called higher or maybe universal power has changed the speaker’s attitude about life, as she sees that there is more to her world than she is able to understand. Whatever the case might have been when Dickinson wrote this poem, our ability to interpret this in numerous ways attests to its power, longevity, and universality.
There is so much more I could say about Dickinson, but I'll keep this focused on the one poem for now...