Edgar Allen Poe's short mystery story "The Purloined Letter" offers an ideal location in which apply some of Jacques Lacan's theories regarding human psychology, and in particular his theory of identification outlined in the essay "The Mirror Stage as Formative of the I Function." Although Lacan is ostensibly discussing a process in childhood development, his discussion of self-identification offers useful insights into the identification (and misidentification) that constitutes the solution to the mystery of Poe's titular letter. In particular, examining the ways in which the Prefect of the Parisian police, the villainous Minister D, and the amateur detective Dupin view each other with an eye towards Lacan's theory will reveal how Dupin ultimately represents the sufficiently self-aware individual, whereas the Prefect has failed to progress through the process of self-identification which occurs during the mirror stage, but rather assumes the identity of an ideal other without truly realizing what this means. Considering "The Purloined Letter" in conjunction with Lacan's essay will reveal that ultimately, Dupin is able to solve the mystery of the stolen letter and fool Minister D. precisely because he understands the process by which identity is formed, a process outlined in "The Mirror Stage as Formative of the I Function."
Before discussing the way in which "The Purloined Letter" uses its characters to demonstrate the important of self-identification and awareness, it will be useful to discuss Lacan's theory in general as a means of providing the necessary critical framework for the subsequent analysis of the story. In his essay, Lacan purports to discuss "a libidinal dynamism, which has hitherto remained problematic, as well as an ontological structure of the human world," in that he seeks to understand the nature of desire by determining the process by which humans establish the notion of an identity that desires, and he finds this process in the mirror stage (Lacan 2). Lacan's discussion ostensibly focuses on a particular development in childhood, but his theory of identification and desire has far ranging applications, including an analysis of "The Purloined Letter."
Although Lacan's larger discussion of the mirror stage is ultimately theoretical and does not directly correspond to an easily definable age or range of ages, he does begin by noting an observable phenomenon in children "from the age of six months [….] up to the age of eighteen months," and briefly discussing this phenomenon will make understanding Lacan's overall theory somewhat easier (Lacan 1). Lacan describes the image of a child in front of a mirror who, "unable as yet to walk, or even to stand up, and held tightly as he is by some support, human or artificial […] nevertheless overcomes, in a flutter of jubilant activity, the obstructions of his support and, fixing his attitude in a slightly leaning-forward position, in order to hold it in his gaze, brings back an instantaneous aspect of the image" (Lacan 1). This image of the child is meant to demonstrate the fact that "the child, at an age when he is for a time, however short, outdone by the chimpanzee in instrumental intelligence, can nevertheless already recognize as such his own image in a mirror," and Lacan's essay is an attempt to describe the potential process by which this recognition occurs (Lacan 1). However, Lacan's theory is generally applicable because it also serves to reveal "the function of the imago," which is "the transformation that takes place in the subject when he assumes an image," and although this will be discussed in greater detail later, for now it is worth mentioning that in the case of "The Purloined Letter," the particular images at play are those of the police inspector, the poet, and the amateur detective (Lacan 1-2, 3).
The function of the imago "is to establish a relation between the organism and its reality," but this relation only ever serves to bring the individual closer to an understanding of reality asymptotically, because self-identification brings with it an attendant realization that individual experience and perception can never result in total understanding as a result of the difference between any individual experience and the perceived experiences of others (Lacan 2, 3). In the case of the mirror stage, gap is revealed in the self-identification of the child as he sees his whole body but lacks the motor function to control it, in contrast with image of the adult holding him (Lacan 2). In reality, of course, the adult is has no more of a total control over his or her self than the child, but the child "anticipates in a mirage the maturation of his power" in the form of the adult, and so sets up a distinction between his individual experience and perceived reality that Lacan argues dictates the functioning of human identification in general (Lacan 2). The recognition of this gap between experience and perceived reality necessitates the adoption of the I function, because the I serves to bridge the gap between the individual and everything else. With this in mind, one can now begin to discuss Lacan's relation to "The Purloined Letter," because the ways in which the central characters identify themselves and are perceived by others constitute the most important elements of the story.
When considering "The Purloined Letter" from a Lacanian perspective, the Prefect of the Parisian police may be seen to represent a kind of unaware, mystified consciousness embodied in the child who has not yet traversed the mirror stage, because the Prefect fails to understand his relation to reality, but the Prefect presents a special case. Instead of merely lacking an understanding of the relation between the individual and reality, the Prefect assumes the identity of the ideal other (represented in the image of the adult) and believes himself to have bridged the unbridgeable gap between experience and reality. The narrator notes that the Prefect "had the fashion of calling everything 'odd' that was beyond his comprehension, and thus lived amid an absolute legion of 'oddities,'" demonstrating how fully the Prefect has failed to reconcile his individual experience with the experiences of others as a result of his assumed identity (Poe 213). This failure is what precludes the Prefect from solving the mystery on his own, because his inclination is to consider Minister D, the thief, particularly dim, and a look at the Prefect's identity as a police officer demonstrates this further.
The prefect states that while Minister D. is "not altogether a fool," the Prefect regards him as lacking intelligence, because he is a poet, which I take to be only one remove from a fool" (Poe 218-219). Obviously, the Prefect's use of "I" shows that he has traversed the mirror stage in the strictest sense, but in the context of the story, he nonetheless represents a failure to appreciate the function of I and its relation to experience and reality, because his self-identification is actually a kind of misidentification. The Prefect imagines himself to actually be the "form in its totality" which serves as the ideal other which individuals asymptotically aspire to be, and so he fails to acknowledge the assumptions which govern his thinking and have influenced his attempt to solve the mystery of the stolen letter (Lacan 3). He does not appreciate how his self-identification as a member of the police force dictates his actions or how that self-identification affects his perception of Minister D, and Minister D. takes advantage of this ignorance by playing to the easily predicted actions of the police, to the point that Dupin tells the narrator that Minister D's "frequent absences from home at night, which were hailed by the Prefect as certain aids to his success," were in reality "only […] ruses to afford thorough search to the police, and thus sooner to impress them with the conviction […] that the letter was not on the premises" (Poe 232).
In other words, rather than attempt to align his experience with that of another, as occurs in the case of the mirror stage and subsequently reveals the limitations of one's own experience, the Prefect, identifying as one of the Parisian police and thus as "persevering, ingenious, cunning, and thoroughly versed in the knowledge which their duties seem chiefly to demand," believes himself to be already privy to the entire range of human experience, with any experiences that fall outside his knowledge being deemed "odd" (Poe 225). The Prefect is unable to solve the mystery "first, by default of this identification, and secondly, by ill-admeasurement, or rather through non-admeasurement, of the intellect with which they are engaged" (Poe 227). Thus, the Prefect represents a kind of misfiring of the mirror stage, where, instead of recognizing the gap between individual experience and the perceived total control in the image of the idealized adult, the Prefect has simply seen the idealized other and assumed it was him, without bothering to confront the fact that his own experience would suggest that he is not nearly as aware as he imagines.