Pain has an element of blank
Although cryptic in language and structure, Dickinson gives her work an instinctually vivid sense of emotion. Her examination of the feeling of pain focuses in on only a few of the subtler nuances of pain that are integral parts of the experience. She draws in on an "Element of Blank" that she introduces in her opening line. In exploring pain, she proposes that this "blankness" is a self-propagating force that is subject to the dynamic forces of time, history and perception, but only to an extent. Her first mention of "Pain" in the first line does not distinguish this particular emotion as being of a particular brand of pain. She substitutes no other words for "pain." By suggesting no other words for "pain," she chooses the most semantically encompassing term for the emotion. She thus gives her work the responsibility of examining the collective, general breadth of "pain." Her alternatives offer connotations that color her usage of "Pain": the sense of loss in "grief" and "mourning" or the sense of pity in "anguish" and "suffering." She chooses the lexical vagueness of "Pain" to embrace all these facets of the emotion.
In introducing the "Element of Blank," it becomes the context that she thus examines pain. The exact context of "Blank" possesses a vagueness that suggests its own inadequacy of solid definition. Perhaps this sense of indefinition is the impression that this usage of "Blank" is meant to inspire. In this context, this "blankness" is suggestive of a quality of empty unknowingness that is supported by the next few lines: "It cannot recollect When it begun." This inability to remember raises a major problem with respect to the nature of "Pain;" namely whether Dickinson is choosing to personify "Pain" by giving it a human quality like memory, or is in fact negating the humanity of making it unable to remember. Several lines below, she suggests that "Pain" does in fact possess some sort of limited sentient ability in recognizing "Its Past - enlightened to perceive." It is very possible that it is the "Pain" that is being enlightened or perceiving. These conscious acts of giving "Pain" some sort of capacity of awareness personify "Pain" to some extent.
In continuation of "Pain's" inability to remember, She proceeds, "It cannot recollect When it begun - or if there were A time when it was not." "Pain's" inability to recollect further personifies it by also making it subject to the human ability to forget. Dickinson thus not only personifies "Pain," but makes it subject to the advance of time. This temporal placement of "Pain", establishes "Pain" within the context of the progression of time by giving it a Past, a Future, and presumably, a Present. Although she places "Pain" within the context of time, she indicates it is not limited by time. "Pain's" inability to remember its own origins strongly suggests an extreme span of time since its inception. This coupled with Dickinson's claim that "It has no Future - but itself," and that "Its Infinite contain Its Past" indicates some connection with the eternal. Here, the "Infinite" suggests not only the infinite sense of eternity, but a more spatial sense of the cosmos and the universality of the experience of "Pain."
This use of the future also serves the notion that "Pain" leads to more "Pain," continuing in Dickinson's reference to "Its Past - enlightened to perceive New Periods - of Pain." In this one stanza, she invokes the future and the past, maintaining that both are key to a cyclicality, where the "Pain" of the past, gives rise to the "Pain" of the present and future. That "Pain" contains an "Infinite" within itself supports this notion of "Pain" being cyclical, as it can thus remain dynamic yet eternal. That it is "enlightened to perceive New Periods" of the sensation of "Pain" suggests that a mechanism of this self-propagation involves the acknowledgement of past periods of "Pain." The "enlightenment" thus becomes some sort of impetus for the propagation of the "Pain" experience as it continues from the past into the future.
To highlight this sense of cyclicality, Dickinson completes the poem with the first word: "Pain." She completes the cycle of her poem in its reiteration, giving it closure, but at the same time, reconnecting it back to its beginning. In doing so, she almost invites the reader to reread the poem, drawing the reader back in to reconsider her meaning. In much the same way, it is this reexamination that "Its Past - enlightened" suggests. Enlightenment comes from some degree of analysis, and is therefore related to the reevaluation of the poem that Dickinson invites.
Dickinson's description of "Pain" as having an "Infinite" also suggests a spatial expansiveness in addition to a temporal one. This sense of "Pain" being limitless echoes the broad definition of "Pain" that she suggests by only using the one term for the experience, and using it only twice. Within the context of the poem, "Pain" is her only subject, and thus encompasses all as far as the work is concerned. The limitlessness of "Pain's" existence within time lends to its sense of overwhelming size when considered "Infinite." It thus suggests an almost tangible existence of "Pain" as a corporeal entity, spanning towards every horizon. This physical perception of "Pain" is not quite palpable due to its lack of physical description in the poem. All that is known about it is its outstanding size. That sense of size alone lends some sort of semi-perceptible physical weight to the description.
In her sole focus on "Pain" within the context of the "Element of Blank," Dickinson chooses such a narrow focus that it is difficult to claim she is putting forth a definitive, encompassing definition of pain. Instead, she writes about a vague, undefined experience called "Pain" that she leaves the reader to define. Note that a semantic distinction must be made between pain and the notion of "Pain" that Dickinson chooses to use. She does not define whether her notion of pain is emotional, spiritual or physical, or perhaps a combination of all three. Her treatment of "Pain" as a semi-cognizant entity, infinite but somehow limited, makes it an abstract, unique concept that necessitates its distinction as "Pain." She does describe "Pain" within the context of the nature of its being. By denoting its infinite nature, she also proposes a capacity to self-propagate. However, she becomes unclear in defining the limitations of these abilities. She explains that it has existed for so long, that it has no memory of its inception, but it is unclear whether that is the fault of "Pain's" inability to remember or "Pain's" infinite history. Dickinson also indicates that "Pain" already has a fated future, one that includes only more "Pain." Despite its infinite nature temporally and spatially, "Pain" is not infinite in a sentient sense, as it is limited by its lack of perception and by the passage of time.
Dickinson leaves much unsaid about the experience and nature of "Pain." She makes no tangible references about the circumstances of her "Pain," leaving the reader to deal only with a indeterminate, abstract notion to relate to. In only relating the "Element of Blank" to its place temporally and spatially, her only hypothesis about the mechanism of "Pain" concerns its cyclicality. Her sole focus on this structure avoids discussion of any other aspect of the experience or sensation of "Pain."