I. Introduction

Perhaps the best-known feature of Arthur Mervyn, or, Memoirs of the Year 1793 (1799) is its depiction of a yellow fever outbreak that gripped Philadelphia in the autumn of the eponymous year. Though the topic has received a fair amount of critical attention, too much of what has been written treats the fever as a trope, limiting its significance by seeing it solely as a component of the novel's larger symbolic economy.[1] In a notable example of this kind of work, Louis McAuley's recent article "read[s] the yellow fever epidemic of 1793 depicted in Arthur Mervyn [...] as a metaphor of the impact of print upon the body politic."[2] While McAuley certainly generates a compelling readings of the novel, any approach that treats the fever in Arthur Mervyn as a figuration of some other ideological or historical item risks eliding the epidemiological situation the novel represents, thus emptying the fever-sequences of all mimetic content. In contrast to such an approach, I propose a reading of Arthur Mervyn that, rather than showing how the fever represents something else, seeks to describe the ways in which the historical presence of yellow fever informs the novel's narrative structure.

In terms of its real-world effects, the statistical record reflects the severity of the 1793 yellow fever outbreak: 17,000 people fled the capital of the republic, while nearly 5,000 died there. At its height the disease claimed upwards of 100 lives per day,[3] and J. Worth Estes has estimated that "anywhere between 50 and 90 percent" of the population were infected but survived.[4] Certainly, then, the sheer magnitude of the disease created a great deal of chaos in Philadelphia. "But," as Benjamin Rush remarked in his account of the event, "a more serious source of the distress of the city arose from the dissensions of the physicians, about the nature and treatment of the fever."[5]

Eighteenth-century physicians faced a great deal of difficulty placing yellow fever within the available frameworks for explaining disease. Theories of contagion did a fairly good job of accounting for ailments like smallpox, which were evidently transmitted via close contact with diseased bodies. Environmental theories of disease, meanwhile, offered plausible explanations for water-borne diseases like cholera and dysentery. But yellow fever challenged both environmentalist and contagionist theories of disease, and this for two reasons. First, yellow fever, like its cousin dengue fever, presents a widely varying range of symptoms: sometimes the pulse is slow, sometimes fast; sometimes the skin yellows, often it does not; sometimes the disease causes a high-grade fever, while in other cases the fever is low-grade, and in some mild cases no fever occurs at all.[6] Confronted with such disparate evidence, many physicians speculated that 'yellow fever' was not one disease but many, and offered differing causal explanations and therapeutic recommendations for what were perceived as different symptom clusters.[7]

The second, and more important, source of confusion was the matter of the disease's etiology, or cause. As Elisha Bartlett wrote in his History, Diagnosis, and Treatment of the Fevers of the United States (1842), "In the multitudinous records of the history and literature of yellow fever, there is no portion so involved in interminable confusion and embroilment as that which relates to its causes."[8] We now know that the flavivirus that causes yellow fever in humans is transmitted by the bite of the A. aegypti mosquito. But to medical practitioners in 1793, the means by which the disease was transmitted remained a mystery. Though it seemed clear to physicians acquainted with yellow fever that simple contact with sick persons was not enough to cause the disease in healthy bodies, it was also evident that exposure to the sick in the presence of certain environmental conditions could in fact lead to the fever's transmission. Because the disease confounded the frames through which Enlightenment-era physicians viewed disease, ideas about its origin, pathology, etiology, and treatment proliferated, becoming objects of widespread and often heated public debate, as well as anxious private speculation.

Once the epidemic struck, it became evident that medical accounts of the disease could no more save the appearances than the physicians offering them could save the sick. Historian J. H. Powell's description tries to capture the emotional tenor of the times:

All the medicines in the pharmacopoeia - the doctors seemed determined to use them all - had not power enough to arrest disaster or erase the horrid scenes presented in these first two weeks of September. Terror and a numb dismay overwhelmed people [...] In the continual failure of the doctors even the bravest lost hope. The city surrendered to a coarsening fear.[9]

At the heart of this affective response to the epidemic was a deeper, epistemic problem. The hidden pathology of yellow fever put a great deal of stress on the explanatory frameworks of Enlightenment-era medical science, and the lack of an apparent cause for the horrific events unfolding in the capital intensified the panic and confusion of those caught up in the outbreak. The disease created a psychic environment of heightened anxiety and nagging uncertainty, presenting Philadelphia's denizens with a particularly horrific set of phenomena for which no satisfactory explanation could be given. This sense of uncertainty, of anxiety over the causes of appearances, pervades the first half of Arthur Mervyn, and it helps to understand the curious blend of Bildungsroman and Gothic plot-structures operating in the novel. In what follows, I will show how the epidemiological and epistemological crisis occasioned by the yellow-fever outbreaks of the late-eighteenth century fundamentally structures Arthur Mervyn's narrative logic.

II. Explaining Yellow Fever

In order to see how the presence of yellow fever led to a crisis in causal thinking, it will be helpful to look at some medical discourses contemporary with Arthur Mervyn that sought to explain the origins and causes of the fever. Two archives command attention in this respect: first, the voluminous literature relating directly to the 1793 outbreak in Philadelphia; second, the medical essays produced in New York by members of Brown's intellectual circle. The first archive, I take it, needs little justification. Not only does Arthur Mervyn deal directly with the 1793 outbreak at the level of content but, as Robert Ferguson has shown, the events depicted in the novel also formed the matrix in which Brown began his intellectual development and started to formulate his ideas about the potentials of the novel form.[10] There are reasons, however, to think that the medical literature written in response to the 1795 and 1798 incidences of yellow fever in New York are even more relevant to discussions of Arthur Mervyn than those surrounding the Philadelphia epidemic. For one thing, Brown began composing Mervyn while convalescing from his own bout with yellow fever, which he contracted during the 1798 New York outbreak. For another, this same wave of yellow fever took the life of Dr. Elihu Hubbard Smith, a physician and former student of Benjamin Rush, who was also Brown's closest friend and supporter at the time.[11] Given Brown's close relationship with Smith, one can imagine that he would have been more familiar with the medical literature produced in response to the events in New York; in any case, the relevance of both archives should now be established.

The responses of the medical community to the outbreaks of yellow fever along America's eastern seaboard gradually polarized into two camps, offering conflicting explanations for the disease. The contagionist school argued that the fever had been imported from abroad, along with infected goods and/or bodies from the West Indies, and that the cause of the disease could be directly ascribed to contact with infected bodies. Opposed to them were the so-called "anticontagionists," proponents of a miasmatic or environmental theories of disease.[12] This group, which included eminent physicians like Benjamin Rush, occasionally admitted that contagion played a role in the causation of some kinds of disease. Still, they emphasized the fact that a locally generated contagious miasma interacted with certain environmental conditions in order to produce illness or not in those who had been - however minimally - exposed to the contagious effluvia. Their etiological explanations tended to be intricate and even mandarin compared to the relatively simplistic, common-sense models offered by contagionists.

This debate between contagionists and environmentalists also figures in Arthur Mervyn. At the height of the epidemic, Arthur, who has already contracted the fever himself, goes searching for his acquaintance Wallace at the home of one Thetford. Finding no one home, Arthur goes to the neighboring houses, where he encounters a physician by the name of Medlicote, who proceeds to educate Arthur about the origins and causes of the disease. Arthur described this process as follows:

[Medlicote] combatted an opinion which I had casually formed, respecting the origin of this epidemic, and imputed it, not to infected substances imported from the east or west, but to a morbid constitution of the atmosphere, owing wholly, or in part to filthy streets, airless habitations and squalid persons.[13]

Thus Medlicote frames the disease environmentally and socially, attributing it to local conditions rather than imported persons. Equally interesting, though, is the fact that Arthur had "casually formed" his contagionist ideas. Contagionism appears in the novel as the "natural" attitude toward disease; certainly it was the most widely believed by people outside the medical profession.[14] The simplicity of contagionist explanations was appealing, and the complexity of competing environmentalist speculations never quite managed to take hold of the popular mind.

Perhaps the most famous medical document emerging from the yellow fever events in Philadelphia is Benjamin Rush's Account of the Bilious Remitting Yellow Fever as it Appeared in the City of Philadelphia in the Year 1793. Rush began composing the treatise in the midst of the crisis, and the book was published early in 1794. In it, Rush advances an etiological account of yellow fever intended, at least in part, as a justification of his own controversial therapeutic methods. His account of the fever's cause is intricate and multifaceted. He asserts that the disease is indeed caused by some kind of contagion, but that the action of the contagion is varied by a host of other factors affecting susceptibility to, and degrees of morbidity resulting from, the fever itself. Thus, according to Rush, the disease's etiology could not be explained simply by asserting the presence of contagion. He writes:

In some constitutions the contagion was at once a remote, a predisposing, and an exciting cause of the disease; hence some persons were affected by it, who had not departed in any instance from their ordinary habits of living [...] But it was more frequently brought on by some predisposing, or exciting cause.

Rush's etiological framework is divided into three distinct classes of causes, and the contagion is figured by Rush as being in fact less directly relevant to the contraction of the fever than other causal mechanisms. The list of potential causes of the disease was notably inclusive, even by the standards of the day: fatigue, heat, intemperance, fear, grief, cold, lack of sleep, and "Immoderate Evacuations" could act either alone or in concert to create illness in a person who had been exposed to the contagion.

Although Rush discusses the disease as a contagion, his emphasis in the Account is more in concert with miasmatic, "anti-contagionist" explanations of the disease's transmission, developed in succeeding years by Seaman, Smith, and other physicians of the younger generation attempting to come to terms with the mysterious causality of yellow fever.[15] In effect, this means that Rush places the influence of contagion on equal footing with other environmental, hygienic, and psychic factors in the contraction of the disease. The etiological picture that then emerges is that of an extremely dense causal web, in which exposure to contagion alone is rarely a sufficient condition for the transmission of the disease.

In contrast to this, the typical contagionist accounts of yellow fever present a much more approachable, rhetorically efficient, and simplified picture of the disease's etiology. One of the more prominent contagionist accounts of the yellow fever in Philadelphia was William Curie's Treatise on the Synochus Icteroides, or Yellow Fever; as it Lately Appeared in the City of Philadelphia (1794). Curie and Rush's accounts agree that the contagion itself and environmental conditions work together to produce the disease. But by emphasizing the causal primacy of the contagion over environmental factors or bodily and mental hygiene, Curie is able to streamline his etiological explanation.

Though the disease we are about to describe was highly contagious, the influence of the contagion was circumscribed to a narrow sphere, for none but those who approached the sick, or to such articles as had been in contact with them, or within the sphere of their effluvia so as to be impregnated thereby were affected.[16]

By virtue of his claim that the contagion emanates directly from the bodies of people infected with the fever - a position Rush and other physicians of the environmental school were unwilling to adopt because of its potentially deleterious effects on society at large - Curie's etiological frame articulates a clear method for escaping the disease. One simply needed to cut off all intercourse with infected persons and, if possible, remove him or herself from the vicinity of the city, in order to remain well. Rush's account likewise attempted to contain the source of the contagion by tying it to the effluvia arising from putrid vegetable matter, in particular a large quantity of coffee which he discovered proximate to the locations where the sickness first struck. But such a claim actually raised more fears than it alleviated. How could one be sure whether they had, or had not, come into contact with such an effluvium? The etiological explanations of the contagionists were the more popular, as they were more easily understood and provided a course of action for those wishing to avoid illness that must have seemed much simpler than Rush's holistic preventive recommendations.

But neither contagionist nor environmentalist theories offered sufficient explanatory models for the disease. William Curie laments the fact:

As the contagious miasmata, or deleterious corpuscles of this contagion, or whatever else it may be supposed to consist of, is neither visible nor can be rendered cognizable to the senses by any means hitherto invented, we can only determine its existence and judge of its nature from its effects.[17]

That is to say, that the causes of the disease were believed to be not simply unknown, but unknowable given the present state of medical science. This being so, Curie urges physicians to abstain from speculative accounts of the disease's cause, and to focus instead on recording and treating of the effects of the disease. As we will see in the next section, it is precisely this valediction on speculative thinking that Charles Brockden Brown's theories of fiction were meant to obviate.

The Philadelphia fever episode polarized contagionist and environmentalist accounts of disease, so that by the time of the 1795 outbreaks in New York, medical practitioners and natural philosophers began to consciously align themselves with either pro- or anti- contagionist ideas. In 1796, in the immediate aftermath of the New York fever episode, Noah Webster edited a volume entitled A Collection of Papers on the Subject of Bilious Fevers, Prevalent in the United States For A Few Years Past. This collection is relevant for our discussion, since many of the papers respond directly either to the Philadelphia outbreak, or the 1795 outbreak, both of which directly influenced Brown. In addition, the collection includes the only extant treatise on yellow fever by Brown's close friend Elihu Smith, which marks the book as particularly important for thinking about the connections between yellow fever and Arthur Mervyn. The first piece in the volume, written by Valentine Seaman, who had apprenticed under Benjamin Rush, concisely communicates the fact that yellow fever seemed to challenge the accepted frameworks for understanding disease. Under the heading of the question "Is the yellow fever communicated by contagion or not?" Seaman writes:

Unshackled from all prejudice, I shall venture to mention several facts that oppose the idea of the contagious nature of this disease, which, if they have not determined by to quit the beaten path of that old established opinion, in which I have been educated, they certainly have staggered me very much.[18]

Seaman goes on to describe a series of facts, many of which he derives from chronicles of the Philadelphia outbreak. Taken cumulatively, the facts make clear that the yellow fever simply does not fit into the models of contagion which Rush and Curie, in part, share. At one point, Seaman cites evidence that

[...] the yellow fever has been produced from other causes than contagion. Does it not then admit of a doubt whether it can possess a power of propagating itself? I confess I am almost ready to believe, that it is either always produced by contagion, or never. It is very difficult to conceive, that two such different causes, should produce exactly similar effects.[19]

Here one can see in the dubiousness of Seaman's language that the yellow fever presented a baffling mix of contagious and non-contagious characteristics. Physicians in the tropics had recorded incidents in which people who had had no contact with any diseased body had nevertheless fallen ill. How then could one account for this disease within the available frameworks, dependent as they were on the concept of contagious effluvia? Seaman's hesitant rhetoric in this passage communicates the fact that his credulity in existing theories of disease was on the wane due to the confounding etiological mechanisms involved in transmitting yellow fever.

As one might expect, the causal explanations offered by the "second-wave" environmentalist physicians collected in Webster's volume were even more complex than the one proposed by their luminary Rush, who, despite his environmentalist leanings, still relied in part on the concept of contagion. Elihu Smith, for example, offers the following causal explanation of the disease:

Owing to a variety of causes [...] I suppose the atmosphere of New-York to have become vitiated, in 1795, to an uncommon degree: that there was either an unusual absence of that principle necessary to support healty life, or an extraordinary concentration, diffusion, or quantity, or some other unfriendly to healthy life [...] With some persons, this condition of the atmosphere, of itself, might be sufficient to produce in them disease. But ordinarily, I believe, the aid of some cause [...] was required to bring the system into a state of febrile action.[20]

Smith's etiology dispenses with the idea of contagion altogether, and instead depends upon a complex and speculative concatenation of environmental causes. His explanation is framed in terms of a "supposition," and he evidently has little patience with the cautions of contagionists like Curie, who would certainly have considered such causal speculations fruitless at best and, at worst, positively harmful. As I will show in the next section, it is precisely this spirit of speculation into the complex causalities underlying phenomenal experience that formed the basis of Charles Brockden Brown's theory of romance, and which he put into practice in his fever novel, Arthur Mervyn.

II. Charles Brockden Brown's Probabilistic Poetics

At the same time that Charles Brockden Brown was working on Arthur Mervyn, as periodic episodes of yellow fever continued to break out along the eastern seaboard of America, he was also busy composing a pair of theoretical texts addressing the potentials inherent in the novel form. In pieces such as "Walstein's School of History," which was published in the interval between Arthur Mervyn's first and second part, Brown articulates a theory of the novel that highlights fiction's ability to deal with uncertainty and probability in ways that elude historical discourse. Understanding Brown's theory of fiction, which, like Arthur Mervyn, was being articulated at the same time that yellow fever outbreaks continued to sweep through the coastal cities of the republic, is a necessary first step to grasping the narrative logic of the novel, and its connection with the epidemiological and epistemological crisis depicted there.

"Walstein's School of History" is not, properly speaking, a critical essay. It is a theoretical statement on the novel couched in terms of a fiction - a discussion of Walstein, an imagined professor of history at Jena loosely based on the figure of Friedrich Schiller.[21] "Walstein," writes Brown, "was conscious of the uncertainty of history." In the course of his historiographic praxis, Walstein came face to face with the fact that

Actions and motives cannot be truly described. We can only make approaches to the truth. The more attentively we observe mankind, and study ourselves, the greater will this uncertainty appear, and the farther we will find ourselves from the truth.[22]

Walstein, thus, comes face to face with the problem of writing true history: though actions may be uniformly and evenly described, motivations remain shrouded in obscurity. But this situation does not close off motivation entirely from the historian's view: "Though no one can state the motives from which any action has flowed, he may enumerate motives from which it is quite certain, that the action did not flow."[23] Thus, for Walstein, historical description becomes, at least where human motivations are concerned, a matter of probability rather than certainty. Still, describing human motivation was not an optional exercise for the historian in Walstein's view, because such moral descriptions were the key to history's educational capacities.

The essay then breaks, and moves on to a discussion of Engel, Walstein's foremost pupil. Engel's revisions of Walstein's method aim at bringing the discourse of history even closer to the discourse of fiction.

Engel [...] thought, like his master, that the narration of public events, with a certain license of invention, was the most efficacious of moral instruments. Abstract systems, and theoretical reasonings, were not without their use, but they claimed more attention than many were willing to bestow. Their influence, therefore, was limited to a narrow sphere. A mode by which truth could be conveyed to a greater number was much to be preferred.[24]

Here, through the figure of Engel, Brown begins to work toward a theory that will legitimate fiction as a "moral instrument" by bringing it into close relation with the discourses of the natural sciences ("Abstract systems and theoretical reasonings"). Brown's essay merges Engel's historiographic method with his own recent novelistic undertakings, as the fictitious description of Engel's work dovetails with the plot of part one of Arthur Mervyn. Engel, Brown tells the reader, in order to write a morally useful piece of history, tells the story of Olivio, a "rustic youth, whom domesticity equality, personal independence, agricultural occupations, and studious habits, had endowed with a strong mind, pure taste, and unaffected integrity."[25] In this description of Olivio, we recognize the outlines of the character of Arthur Mervyn's eponymous hero. The tie becomes yet more explicit, as Brown describes Engel's history: Olivio [Arthur] becomes entangled with the conniving Semlits [Welbeck], becomes infected with a "pestilential disease," and falls under the care of a physician [Dr. Stevens, Arthur Mervyn's frame-narrator], by whom he is nursed back to health.

In "Walstein's School of History," then, Brown is concerned to defend the narrative authority of speculative historical fictions. By expanding the factually descriptive enterprise characteristic of historiography to include probabilistic assessments of human motivation, Engel's project - which, as we have seen, is a stand-in for Arthur Mervyn itself - is situated at the border between history and romance which, for Brown, is the discursive line dividing certainty from uncertainty. What then emerges is a self-reflexive statement about Brown's novelistic poetics, one that attempts to ground the practice of writing fiction in a conscious expansion of historical discourse to include events whose causes are shrouded in obscurity.

In a near-contemporary essay entitled "The Difference Between History and Romance" (1800), Brown expands on the idea that fiction distinguishes itself from history by virtue of its ability to deal with the uncertainties attending causal descriptions of events. Brown begins by restating the conventional wisdom about what separates history from fiction, namely, that history describes real events and persons while "romance" describes the fantastic, the irreal, and the imaginary:

History and romance are terms that have never been very clearly distinguished from each other. It should seem that one dealt in fiction, and the other in truth; that one is a picture of the probable and certain, and the other a tissue of untruths; that one describes what might have happened, and what has actually happened, and the other what never had existence.[26]

While the terms of the division seem theoretically sound, when applied to a given historical or 'romantic' performance, the distinction between history and romance tends to fall apart. When the historian speculates on human motives, or when the romancer bases her narrative on factual events, it becomes clear that such artificial means of delimiting history and romance fail to do justice to the reality of those modes of production. In place of such an impoverished understanding, Brown posits the following account of the difference between history and romance:

The observer or experimentalist, therefore, who carefully watches, and faithfully enumerates the appearances which occur, may claim the appellation of historian. He who adorns these appearances with causes and effect, and traces the resemblances between the past, distant, and future, with the present, performs a different part. He is a dealer, not in certainties, but probabilities, and is therefore a romancer.[27]

Hence, in this description, the difference between history and romance consists in the "adornment" of bare factual reportage with a probabilistic causal logic. For Brown, then, the discourse of the novel is located not at the border between "what actually happened" and "what never had existence," but at the border between certainty and uncertainty, the interface between appearances and their causes.

Thus romance, for Brown, is not confined to the novel, or to history: it is also the discourse of speculative science. It is an experimental discursive practice that links causes and effects to one another by means of a probabilistic logic, one that answers the human need to understand the present in terms of the past, and to calibrate present actions based on potential consequences in the future. On the subject of this need for "romantic" speculation, Brown writes:

Narratives, whether fictitious or true, may relate to the process of nature, or the actions of men. The former, if not impenetrable by human faculties, must be acknowledged to be, hitherto, very imperfectly known. Curiosity is not satisfied with viewing facts in their disconnected state and natural order, but is prone to arrange them anew, and to deviate from present and sensible objects, into speculations on the past or future; it is eager to infer from the present state of things, their former or future condition.[28]

While "Walstein's School of History" focuses almost exclusively on the uncertainty surrounding human motivations, here is becomes clear that Brown's "romantic" writing also takes up the issue of the "process of nature," or the causal chains that join natural phenomena. In a later passage, Brown makes the connection between scientific speculation and "romantic" discourse even more explicit. He writes:

An electrical historian will describe appearances that happen when hollow cylinders of glass and metal are placed near each other, and the former is rubbed with a cloth. The romancer will replenish the space that exists between the sun and its train of planetary orbs, with a fluid called electrical; and describe the modes in which this fluid finds its way to the surface of these orbs through the intervenient atmosphere.[29]

Because "romance" is a speculative enterprise, Brown argues, it ought not to be judged on the basis of factual accuracy, but rather by the degree to which its causal explanations of events seem probable: "Historians can only differ in degrees of diligence [i.e. inclusiveness] and accuracy, but romancers may have more or less probability in their narrations."[30]

Throughout "The Difference between History and Romance," Brown conflates the causality of purely physical phenomena like electricity with the motivations that lead human agents into action. This is a particularly telling rhetorical move, and it comes to bear specifically on the plot structure of Arthur Mervyn. As Arthur develops through the course of the novel, he improves both as a moral agent and, through his medical training, as a natural scientist. His ability to peer into the motives of others, and to discern the outcomes of his own actions, is mirrored by the emergence of his ability to understand the causes of an illness, and administer effective therapies. Turning now to the novel, I hope to show how the plot-structure of Brown's novel stages Arthur's progress from a young man with an impoverished sense of causal logic, into a mature and fully educated adult with the ability to see into the human motivations and natural processes that form the causal matrix of events.

III. Arthur Mervyn's Causal Education

At the beginning or Arthur Mervyn, the reader is introduced to the eponymous protagonist whose moral, intellectual, and social development are the central concern of the novel's Bildungsroman plot-structure. Arthur has been discovered, lying ill with the fever, by one Dr. Stevens, who, once he has nursed Arthur back to health, asks for details regarding his history. Arthur then begins his narrative, thinking back over the chain of events that has led him to Stevens' doorstep. He introduces himself to Stevens as a one-time naive country rustic, whose circumstances at home had grown intolerable and who, as a result, ventured into Philadelphia to seek his fortune. The night before Arthur set off for the city, he tells Stevens, he was kept awake by anxious conjectures about his eventual fate. He reflects:

No wonder the prospect of so considerable a change in my condition should deprive me of sleep. I spent the night ruminating on the future, and in painting to my fancy the adventures which I should be likely to meet. The foresight of man is in proportion to his knowledge. No wonder that in my state of profound ignorance, not the faintest preconception should be formed of the events that really befell me.[31]

Here, Arthur lays out the fundamental problem to which his progress through the novel responds. Arthur's coming-of-age story involves moral, social, affective and scientific development, but what binds all these separate spheres together is a pursuit of adequate "foresight," the ability to formulate probable conjectures relating a present state of affairs with those of the past or, as here, of the future. The central psychic drive for Arthur is "curiosity," the same feature of the human intellect that, in "The Difference Between History and Romance," leads the romancer "into speculations on the past and future." As Arthur tells Dr. Stevens, "My temper was inquisitive, but there was nothing in the scene to which I was going from which my curiosity expected to derive gratification."[32] Arthur's belief that he will find no objects real interest in Philadelphia, which he here views with all the retrospective irony due him after his adventures there, results from his incapacity to accurately "paint" the scene "to [his fancy." The only remedy for such a lack of knowledge, and the impoverished sense of consequence it occasions, is experience - which is precisely what the novel's plot aims to provide its hero.

The plot proceeds by first accumulating a series of improbable events, and then unwinding their significance. Each successive episode confronts Arthur - and the reader - with a mysterious set of circumstances, the significance of which is to be unfolded in the sequel. After arriving in the city, Arthur happens to encounter another young man from the country, by the name of Wallace. Wallace offers Arthur lodging for the night and, after some rudimentary reflection on "the possible designs" and motives underlying Wallace's kindness, Arthur agrees to accompany him to the house of his employers, the Thetfords. On arrival there, Wallace - acting on motives that remain completely opaque for the majority of the novel's first part - locks Arthur into the Thetfords' bedchamber closet. Immured in this "romantic and perilous"[33] situation, Arthur overhears a conversation concerning a plot to defraud a wealthy Nabob of an enormous sum of money. After a narrow escape, Arthur wanders through Philadelphia, finally winding up at the gate of a mansion on the outskirts of the city which - improbably enough - belongs to Welbeck, the selfsame Nabob upon whom Thetford had set his designs. Thus Arthur is drawn into the novel's complex web of subplots via a series of chance encounters that simultaneously dramatizes his inability to formulate probable speculations, presents him with a mystery to gratify his curiosity, and expands his experiential palate.

Arthur is then accepted into Welbeck's home as his personal amanuensis, and the plot of the novel's first part begins to thicken. The encounter with Welbeck presents Arthur with a host of unanswered questions: how did he attain his wealth? why did he insist on Arthur's secrecy? and, most importantly, who was the beautiful young woman residing with Welbeck? After spending a couple of days with Welbeck, Arthur wanders through Philadelphia:

After viewing various parts of the city; intruding into churches; and diving into alleys, I returned. The rest of the day I spent chiefly in my chamber, reflecting on my new condition; surveying my apartment, its presses and closets; and conjecturing the causes of appearances.[34]

Arthur's curiosity has been awakened as he goes about the city and his room, peering into its secret places. At the same time, his imagination is at work "conjecturing the causes of appearances" - in other words, working on his skills as a "romancer," a seer into the causal nexus out of which events arise.

As the plot moves closer to the fever sequence that will end part one, the appearances are undercut as Welbeck's secrets come unwound: his kindness is revealed as greed, his vast wealth as abject poverty, and his daughter Clemenza as his unwilling captive. Thus Arthur is cast into a state of anxiety and dubiety, in which state he flees into the country, and takes refuge at the Hadwin farm. The Hadwins, however, turn out to have connections with Wallace, the youth by whom Arthur was drawn into his trouble with Welbeck. Moved by his sympathy for Wallace, Arthur plans to return to the city in order to rescue him. Just as he had before his first venture to Philadelphia, Arthur turns his thoughts toward the future, in order to gauge his course of action, and the degree of his risk:

It is true that my own life will be endangered; but my danger will be proportioned to the duration of my stay in this seat of infection. The death or flight of Wallace may absolve me from the necessity of spending one night in the city.[35]

Arthur's prognostications are still wrapped up in ignorance, insofar as he has yet to encounter Medlicote, and so is still working under his "casually formed" folk-contagionist ideas about the causes of the disease. But he has learned enough through his previous experience to recognize the limits of his speculations:

My stay, however, may be longer than the day. I may be condemned to share in the common destiny. What then? Life is dependent on a thousand contingencies, not to be computed or foreseen. The seeds of an early death are sown in my constitution. It is vain to hope to escape the malady by which my mother and my brothers have died. We are a race [...] exposed, in common with the rest of mankind, to innumerable casualties; but if these be shunned, we are unalterably fated to perish by consumption.[36]

Arthur's curious fatalism here and elswhere is one of the strangest elements of the way the novel presents his psychology. In line with a reading of Arthur Mervyn that sees etiology, causation, and probability as central to its narrative architecture, I suspect that Arthur's morbid speculations are to be read as a fantasy of escape from contingency, a yearning for death as relinquishing all agency to necessity. Because Arthur's decision to put himself at risk in order to rescue Wallace are based on this reasoning, we infer that Arthur's moral sentiments are still the result of an illusory sense of probability. But where before Arthur's fault stemmed from his inability to conjure "the faintest preconception" of what would befall him, here the error consists in the cockiness of unwarranted certainty about the future.

Arthur's encounter with the yellow fever is cast in similarly fatalistic terms. Arthur wanders through the Thetfords' home searching for Wallace:

I mounted the stair. As I approached the door of which I was in search, a vapour, infectious and deadly, assailed my senses. It resembled nothing of which I had ever been sensible. [...] Some fatal influence appeared to seize upon my vitals; and the work of corrosion and decomposition to be busily begun.[37]

Arthur believes himself to be sick, outside of the reach of uncertainty in a domain of fatalistic certainty: "So far the chances in my favor were annihilated. The lot of sickness was drawn."[38]

Arthur's deterministic view of his situation is shattered in the next chapter, when he encounters the enlightened physician Medlicote. Commenting on the details of Arthur's trip into Philadelphia, Medlicote councils him:

Your undertaking, said he, has certainly been hazardous. There is poison in every breath which you draw, but this hazard has been greatly increased by abstaining from food and sleep. My advice is to hasten back into the country; but you must first take some repose and some victuals.[39]

Medlicote's makes his environmental leanings clear in this passage, and he also restores Arthur's condition to one with a potentially favorable outcome, redeeming him from the fatalistic musings of the preceding chapters. Arthur's education about the yellow fever, one that marks the beginning of his interest in becoming a physician, is also, crucially, an education about causality. First, Medlicote discounts Arthur's "causally formed" ideas about yellow fever, "imputing it, not to infected substances imported from the east or west, but to a morbid constitution of the atmosphere, owing wholly, or in part to filthy streets, airless habitations and squalid persons."[40] Secondly, Medlicote reveals to Arthur that he still has agency - that his fate is not yet written in stone.

Arthur's etiological education, then, combines an understanding of the origins and causes of the yellow fever with an education about narrative. Medlicote saves Arthur from his fatalistic view of his future, thus allowing the novel's Bildungsroman plot to advance. In this scene, an understanding of the yellow fever yields to an understanding about the general relation between cause and effect, which Medlicote figures both as complex, and always open to the actions of the agents that operate within a given causal nexus.

In terms of its generic orientation, the first part of the novel may be read as an overcoming of Gothic romance by means of a narrative of education as development, as Ausbildung, which continues in the novel's second part. The gothicized representation of yellow fever highlights the anxiety created when appearances resist or refuse causal explanation. As is characteristic of the gothic, this gap between cause and appearance becomes the source of dramatic tension and suspense in Arthur Mervyn. Arthur's education in causal relationships - the fundamental business of the novel's coming-of-age plot-structure - allows him to bridge this gap by means of what Brown calls "romance." As we have seen, Brown uses this term to denote an ability to propose a - more or less credible, more or less probable - cause from a given set of empirical data. By the time that Arthur arrives at Dr. Stevens' doorstep, he has been restored to agency through Medlicote's enlightening influence, but this return to agency is also a return to a probabilistic world, one in which a measure of uncertainty attends every explanation, every action. Arthur has been given the means, though, to cope with this uncertainty. The very fact that Arthur is able to unfold his own story to Dr. Stevens implies a certain kind of narrative power or control, an ability to "arrange [facts] anew" in a way that highlights the duration of events by connecting cause with effect, producing not a catalog of curious incidents, but a story. The fact that the novel's first part is in an analeptic mode means that both Arthur and the reader know how the story ends - but only Arthur knows how the story unfolds, by what series of events he winds up where he started. The narrative control with which Arthur tells his story is one dividend of his causal education. The extended performance of Part I showcases, for Dr. Stevens' benefit and for the reader's, Arthur's development from ignorant rustic to medical apprentice. While his development is by no means complete, even by the end of the novel's second part, Arthur has at least become a fair enough romancer and etiological thinker to unfold a a complex and often improbable-seeming series of events in a way that compels attention.

IV. Causality in Epidemiology

In a recent article on "Causality in Epidemiology," Paolo Vineis describes the development of epidemiological thought since the nineteenth century as movement "from monocausality to multiple causation." The development of germ-theory by Pasteur and Koch marks "the triumph of a linear mono-causal (Aristotelian) concept of cause" over the older, environmental models. This era, dominated by what Vineis calls "the Pasteur-Koch paradigm," were showed wanting when attention was turned to illnesses like heart disease and lung cancer, whose etiologies were not due to a single and well-defined necessary cause. "Cases of lung cancer," Vineis writes, "are not characterized all by the same exposure, but they share partly overlapping constellations of causes." Etiological explanations become even more complex when dealing with maladies like anorexia or depression, and Vineis posits that current epidemiologists are currently in the midst of a third era of causal thinking that will develop more nuanced techniques for understanding the pathologies of such diseases.

Does Arthur Mervyn have a place in this history of etiological thinking? It might appear not. It was not written by a physician or specialist. It was composed at a time when medical knowledge was based on false assumptions. And it lionizes a climate-based way of thinking about disease that later discoveries proved to be radically incomplete and often incoherent. Still, I think Brown's novel does deserve a place in this history, if for no other reason than that it emphasizes the complexity of the causal webs that surround the events of our lives.

It is perhaps an overstatement to say that Arthur Mervyn arrives proleptically at an understanding of cause that resembles current views on the complex causation of disease. However, the novel's nascent environmentalism does provide contemporary thinking about public health with an important precursor. The Philadelphia yellow fever outbreak marked a watershed moment in the development of epidemiology as a distinctive discipline, and looking back at this moment can help us to understand how complex causal models, while playing a crucial role in risk assessment and other epidemiological enterprises, remain largely unpopular. Arthur Mervyn's great advantage is that it couches a message about complex causation in a popular form. With the collapse of the housing bubble, the explosion of the Deepwater Horizon oil rig, and the phenomenon of mass animal death, causation is very much at the forefront of contemporary American social, political, and environmental thinking. Thus the lessons Arthur learns are as timely now as they were at the turn of the eighteenth century. To ignore them is tantamount to relinquishing agency, and submitting ourselves to the tyranny of unchecked risk.