A philosophy of metaphysics is judged by its simplicity, universality, and comprehensiveness—that is, by its capacity to explain not only the nature of being, or substance, but also the nature of non-existent things—such as phenomena—which being may not encompass. Aside from the metaphysical claims of scientific materialism (atomism, quantum mechanics, string theory, etc.), Leibniz's theory of monads, developed in the late seventeenth century, is generally viewed as the most powerful and consistent modern metaphysics. In this brief essay, I'd like to consider whether Leibniz's theory of substance, outlined in the Monadology, might help to explain a phenomenon that appears to be remote—almost inconceivably remote—from philosophical metaphysics: modern nightlife. Although I understand nightlife quite literally as a mode of experience which has evolved historically in the anomalous space of the nightclub, I also understand nightlife as a phenomenon determined in part by the history of certain kinds of vernacular poetry and therefore sharing with poetry a kind of lyric substance. More precisely, in relation to Leibniz's theory of substance, I am interested in the labyrinthine topology of nightlife, especially the topos of the nightclub, a place or event infused with verbal reflection (hence its adulterated substance); its ambiguous relations to what lies outside its windowless space; its open secrecy (which amounts to a spectacle of obscurity); and its sociological, topographical, and even architectural obscurity.

Leibniz is known today principally as one of the founders of modern logic, as perhaps the greatest mathematician among the major European philosophers (he was the inventor of infinitesimal calculus), and, as I've indicated, for his metaphysical system, summarized near the end of his life in a text known as the Monadology  (Leibniz never gave it a title)—a treatise of some twelve pages written in French in 1714. Leibniz's metaphysical doctrine, which has stirred controversy among philosophers and admiration among poets since its formulation in the 1690's, holds that nothing is real except "monads," simple entities without parts, possessing "neither extension, nor shape, nor divisibility"—that is, without sensory or material properties (Leibniz, Monadology 213). Monads, according to Leibniz, are "incorporeal automata," consisting solely of perception and appetite—indeed, perception (a term used by Leibniz in a manner requiring careful explanation) is substance, in a world defined by mind-like, immaterial entities (Monadology 215). Although monads—the "true atoms of nature"—are beings of reason, they supply, in aggregate, the a priori conditions of all material bodies, a conception granting only partial reality to matter (insofar as it may be understood as a "mode" of monadic perception) and subjecting the status of material entities to endless debate.

"Each monad," according to Leibniz, "is a living mirror, or a mirror endowed with internal action, which represents the universe from its own point of view and is as ordered as the universe itself" (Leibniz, "Principles" 207). Substance therefore, according to Leibniz, is essentially a medium—a mirror in constant flux. Yet monads have no direct or causal interaction with other monads, or with the phenomenal reality designed—and "perceived" indirectly—in concert with other monads. Hence, perception, the very substance of monads, occurs without external influence: a paradox defining the essential lyricism—that is, the obscurity—of monadic being. All monadic relations are therefore immanent relations. Leibniz's theory of the solipsistic perception of monads and his explanation of relations between these hermetic substances—each with its own imperfect perspective on the universe—provides the basic terms for an explanation of the open secrecy of the modern nightclub.

Leibniz's Monadology attracted the interest of Novalis, Friedrich Schlegel, and other writers associated with the Athenaeum magazine towards the end of the eighteenth century. For the young experimentalists of the Frühromantik in Germany, the appeal of Leibniz's ideas could not be separated from his philosophical style.[1] Schlegel, placing Leibniz "among the greatest masters" of a "thoroughly material wit," describes his manner of writing and thinking as falling between science, philosophy, and poetry: "The most important scientific discoveries are bon mots of this sort—are so because of the surprising contingency of their origin, the unifying source of their thought, and the baroqueness of their casual expression. . . . The best ones are echappés de vue into the infinite. Leibniz's whole philosophy consists of a few fragments and projects that are witty in this sense" (Schlegel, Athaneum Fragments, Fragment 220).

Implicated in what may be called "a cult of infinity" among members of the Jena Circle, Schlegel deduced from Leibniz's attempt to free mathematics from geometric intuition a "language of infinity" (corresponding to the "necessary fiction" of infinitesimal calculus) in the guise of the fragment. Indeed, Schlegel's most important stylistic innovation (practiced in concert with his friend Novalis)—the literary-philosophical fragment—clearly takes inspiration not only from the philosophy of the monad, but from the monadological style of Leibniz's treatise: "A fragment, like a miniature work of art, has to be entirely isolated from the surrounding world and be complete in itself" (Schlegel, Athaneum Fragments, Fragment 206). Moreover, the fragment and the riddle are united in Schlegel's mind by the substance of wit—a monadic substance—which somehow exceeds its comprehension: "A good riddle should be witty; otherwise nothing remains once the answer has been found" (Schlegel, Critical Fragments, Fragment 96).

Though Leibniz's "witty" philosophical style—a "chemical wit," in Schlegel's phrase—furnished a cool example of the new aesthetic ideology of the enigma, his appeal to the Jena Circle was not primarily stylistic. At a moment in literary and cultural history when the I-know-not-what of aesthetic experience was being redefined in revolutionary ways, the "new Leibniz" emerged as the philosopher of the German counter-Enlightenment, a rallying point—in part for his ostensibly unsystematic approach—for anti-Kantian views. Probably most important to the new aesthetic formulated by Schlegel and his counterparts was Leibniz's theory of unconscious perception (petites perceptions)—the first modern conception of the unconscious. This form of perception is characteristic of all substances, including objects.[2] In addition, Leibniz's theory of monadic perception—a psychology of ontological substance—provided the philosophical rationale for placing sensation, intellection, and feeling on a continuum, so that perception, or feeling, might be regarded as a "confused" form of thinking, yet remain clear in its effect.

One could therefore begin to conceive of perceptions that are "clear, but confused"—a formulation of ontological substance (since perception is substance in the Monadology) that relies on a complex rhetoric of clarity and obscurity. What's more, the obscurity—the perspectival nature—of monadic perception is not simply unavoidable: it is constitutive of individual substances. In the context of this dynamic transvaluation of obscurity, the evocative monad became for Fichte a model of the self; for Novalis a template of the natural object (think of Keats' negative capability); and for Schlegel a principle of aesthetic form.[3] The psychological inflection of monadic substance thus activated a series of transitive relations between Romantic conceptions of subjectivity, objecthood, and aesthetic form—all oriented around the axis of poetological research.

The essential features of the Romantic Leibniz survive into the twentieth century in surprising ways. The Marxist critic Georg Lukacs, for example, called the work of art "ein fensterlos Monad " (a windowless monad) in an early essay on aesthetics, published in 1917 (16). The most illustrious (and discreet) modern student of the Monadology in its Romantic aspect was, curiously, another Marxist, Walter Benjamin—an indication, perhaps, of the latent sociological prospect of the monad. Benjamin's dissertation director, Richard Herbertz, published a book on Lebniz, Die Lehr vom Unbewussten in System des Leibniz (The Doctrine of the Unconscious in the System of Leibniz) in 1905, a work that almost certainly influenced Benjamin's dissertation, "The Concept of Criticism in German Romanticism," which views the "medium of reflection" posited by Schlegel and Novalis as essentially monadological. Although Benjamin's career as a Leibnizian idealist reached its peak and breaking point in his formulation of the guiding principles of The Origin of the German Mourning Play in the mid-1920's, his thinking never lost its Leibnizian cast.[4]

From a phenomenological perspective, the correlation between modern nightlife and metaphysical substance begins with the intuitive resemblance between the hermetic forms of the monad and nightclub, each constituting a place, a topos, which has disappeared from the map of the world. Yet this correspondence is more than intuitive, as Leibniz employs architectural analogies to characterize the formal—that is, non-intuitive—properties of the monad. Leibniz describes monads as "architectonic models" (echantillons architectoniques) of a universe from which each monad is nevertheless radically isolated by its incorporeal substance (Leibniz, Monadology 223). Further, in a famously eccentric and remarkable image, he declares, "Monads have no windows through which something can enter or leave" (Leibniz, Monadology 214). Walter Benjamin later indentified the windowless monad as the incorporeal paradigm of his conception of the Parisian Arcades. Describing the Arcades Project as a fragmentary vision of "the true city—the city indoors," Benjamin explains, "What obtains in the windowless house is the true. And the arcade, too, is a windowless house. The windows that look down on it are like loges from which one gazes inside, but one cannot look out from them" (cited in Fenves 273-274 n14). The introverted vista of the windowless arcade corresponds in remarkable ways to the naked hermeticism of modern nightlife.

One must bear in mind, however, that Benjamin's monadology of the Arcades always reverts to an understanding of language and its role in configuring experience, a deductive regression also characteristic of Leibniz's formulation of monadic substance. Furthermore, Benjamin's appropriation of Leibniz's monadology betrays a significant debt to the poetological theories of early German Romanticism—especially to Novalis and Friedrich Schlegel, whose lyric monadologies remain, as I've indicated, the most significant literary engagements with Leibniz's philosophy. Ultimately, because the basic elements of Leibniz's thought (symbolic logic and metaphysics) betray the influence of his early thinking about artificial languages and his lifelong interest in etymology, one should emphasize that Leibniz's formulation of ontological substance (monads) and his understanding of logical procedures reflect, essentially, a conception of linguistic being.

Leibniz's analytic project yields a methodological "device" capable of navigating by "calculation" and with "the aid of signs" what he calls "the labyrinth of the continuum" (the maze of phenomenal appearance), or other structures characterized by obscurity—such as the branching of historical languages.[5] In keeping with the rhetoric of labyrinthine forms (which may be compared to the topographical obscurity—the garbled location—of the underground club), Leibniz often refers to the analytic key, or calculus, as the "thread of Ariadne," echoing his conception of the "Ariadne thread" of etymology.[6] Most importantly, and consistently, Leibniz conceives of the calculus—the Ariadne thread—as a system of "rational writing," a "philosophical language," or, more commonly, a "universal characteristic":

No one should fear that the contemplation of signs will lead us away from the things in themselves; on the contrary, it leads us into the interior of things. We often have confused notions today because the signs are badly arranged, but then with the aid of signs we will easily have the most distinct notions, for we will have at hand a mechanical thread of meditation [emphasis added], as it were, with whose aid we can easily resolve any idea whatever into those of which it is composed. (Leibniz, letter to Tschirnhaus, May 1678, Philosophical Papers and Letters 193)[7]

So great are the analytic powers of this "mechanical thread of meditation," elsewhere compared to the inventions of the microscope and the telescope, that Leibniz describes it as a "guiltless kind of magic."[8] Though Ariadne's thread reveals itself to be a "mechanical"—that is, logical—instrument that allows one to calculate one's way out of the maze, the magical thread and the riddling topography of the labyrinth remain, in essence, linguistic phenomena.

The verbal topology of monadic substance offers a useful model for the secret world of the club—a placeless place—and for the infidel poetry associated with the topology of nightlife. For the tradition of English poetry harbors a kind of rude song written in cant, the jargon of the demimonde, garbled and misplaced by design, which draws the reader into an historical underworld of taverns and nightclubs. The expressive correspondences between various modes of obscurity—verbal, topographical, even sociological—are essential to understanding the explanatory value of the Monadology as a model for the substance of nightlife. Placing poetry in this particular way—tracing lyric to one of its hidden sources—helps to recover a little-known vernacular tradition, a genre of "lost" poems; yet it also raises, more generally, certain theoretical questions about configurations of place, or placelessness, in language and about the topography of poetic form. Equally important, the taverns and clubs of the historical underworld may be described as obscure in various ways that thereby match, or compound, the verbal obscurity of "infidel" poetry.

These correspondences confront the reader, for example, in a line of Hölderlin's poem "The Rhine," which states: "Ein Rätsel ist Reinentsprungenes" ("Pure of source is the riddle") (Hölderlin 73). The purity of the river's source is not, according to this statement, a mystery—a mode of obscurity that is unresolvable—but a riddle: "a device of language," according to Paul de Man, "that can, in turn, be deciphered only by another operation of language" (de Man 206). Thus, the river's enigmatic source appears to be defined by the "operation" of a verbal figure. At the same time, however, the principle of verbal obscurity, conventionally defined as a failure of meaning or communication, appears in Hölderlin's poem as a topographical phenomenon. Places characterized by obscurity appear objectively in the world, though their exact location may be unmarked or unknown. Whether marked or unmarked, however, the place of the riddle (or the riddle of the place) resists discovery. Verbal obscurity, the place of the riddle, therefore expresses the condition of that which is neither lost nor found, but undiscovered or unanswered.

As a form of secrecy, nightlife and the history of nightlife describes a topology, a study of lyrical sites, in language and in correspondingly anomalous material environments. Giorgio Agamben stumbles upon this site when he discovers in the principle of the topos a model for understanding the lyrical chamber of the stanza. The poetic stanza may be thought of as a topos, according to Agamben, if we

accustom ourselves to think of 'place' not as something spatial, but as something more original than space. . . . Only a philosophical topology, analogous to what in mathematics is defined as analysis situ (analysis of site), in opposition to analysis magnitudinis (analysis of magnitude), would be adequate to the topos outopos, the placeless place. (Agamben xviii-xix)

The poetic topos of the stanza exists, under these terms, without material extension or "magnitude," like the monad or the clandestine place of the nightspot, insofar as the actual sites of nocturnal culture continually elude material and pragmatic definition and thereby approximate the ambiguous substance of verbal reality. Reading the stanza into the topos (and vice-versa) allows Agamben to define poetry generally as "a topology of the unreal" (Agamben xviii)—a phrase that aptly describes the partial world (demimonde) of nightlife as well.

Taverns and nightclubs are places where casual social interaction, business, and even crime coexist in a place governed ostensibly by pleasure. They are also sites where the illicit and often subversive habits or "trades" of the demimonde become intelligible—and available—to members of law-abiding society. As a verbal site, a place in poetry, the topology of the nightspot has its origins in the drinking songs of the canting tradition. "Cant," the earliest term for slang in English, refers to the specialized jargon of the criminal underworld, employed by thieves, beggars, prostitutes, and vagabonds. Evident since the fourteenth century, a submerged tradition of poems written in canting speech has developed with increasing resonance, sometimes in conjunction with the dominant literary tradition. Cant is thus the idiom of a vernacular tradition embedded in the "flash crib," the place where flash talk, or cant, is spoken. In this sense, the rhymes of the canting crew, embedded in a variety of literary texts, function as sources of historical and profane illumination, fitfully and haphazardly lighting the topography of nightlife.

One may present evidence evoking a history of nightlife, yet one must always bear in mind that the nightlife of the past survives for the most part in cant, in writing: a place finding its tempo, its economy, its afterlife—its charm—in language. Since much of the evidence comes from plays and ballads, the tavern or nightspot is essentially a place contingent on literature, and on vernacular poetry in particular, for its specific qualities and its enduring substance. The chiaroscuro of the canting song, its dappled sense and senselessness (what Hopkins would call its "pied beauty"), its rude but alluring textures: these verbal qualities constitute the very substance of the nightspot and its clandestine society.

One should not presume, however, that the inescapably verbal substance of nightlife under these conditions is somehow secondary to the physical reality of nightlife, either in the past or the present. For that reality is fundamentally dissolute, its very existence placed in question by the obscurity of its material conditions: its nomadic timetable and improvised venues; its revolving, unmarked locations; its nameless (or nicknamed) and promiscuous society. That is to say, the external conditions of nightlife continually revert to the material ambiguity of verbal reality, thereby betraying the essential inwardness and incommensurability of its primary substance. The appearance of nocturnal culture thus always follows the logic of disappearance, dissolving into the material and social fabric of the world, in order to secure a location which betrays no outward aspect—an impossible place, an open secret, in the façade of the city. From this perspective, the lyrical topos of nightlife in poetry is the primary form of that which takes place, secondarily, in the world. The secretive and senseless charm of the canting song would thus be the truest form of nightlife, in contrast to the more explicit and therefore degraded version of it taking place in the streets.

In order to understand the hermeticism of the verbal topology comprising the substance of nightlife, and in order to articulate the various modes of obscurity intrinsic to the nightspot, one must attend more closely to the solipsistic relations characteristic of monadic substance. Leibniz consistently emphasizes the partial or perspectival nature of monads as well as their solipsism, as in the following citation: "a monad, in itself and at a moment, can be distinguished from another only by its internal qualities and actions, which can be nothing but perceptions (that is, the representation of the composite, or what is external, in the simple" (Leibniz, "Principles" 214). All monadic action is, furthermore, spontaneous: "the monad's natural changes come from an internal principle, since no external cause can influence it internally" (Leibniz, Monadology 214). Perception thus constitutes the only possible form of monadic relation, and the changes from one perception to another constitute the only possible form of monadic action. Nothing therefore exists, according to Leibnizian metaphysics, but an endless series of immanent representations coordinated among the infinity of monads—though the term "representation" fails, as it implies an extrinsic relation, to capture the autistic nature of monadic perception. Thus, while Leibniz declares that every "monad represents the whole universe" and that "the nature of the monad is representative," we must take care to understand representation in this context as a species of perception characterized by immanent relations (Leibniz, Monadology 221, 220).

Leibniz's theory of monadic "perception" is obscure in part because it does not involve—in its most rudimentary form—the experience of sense perception, or sensation; it erodes the absolute distinction (dear to Kant) between thinking and perceiving—an idea of explosive importance for Romantic poetics and epistemology. The riddle of solipsistic perception prompted Bertrand Russell to explain, "Perception is marvelous, because it cannot be conceived as an action of the object on the percipient, since substances never interact. Thus, although it is related to the object and simultaneous with it (or approximately so), it is in no way due to the object, but only to the nature of the percipient" (Russell 132). In a sense, as Fabrizio Mondadori observes, "it is as if what is perceived (whatever it may be) were not there at all: given the denial of causal interaction, what is (said to be) perceived might as well melt into thin air" (32). Although no direct, physical or causal relation obtains between monads, or between a monad and the phenomenal world, the disparate perceptions and "appetites" of individual monads are synchronized by what Leibniz called expressive correspondences. The principle of expression, which is essential to the coherence of Leibniz's metaphysic, therefore accounts for the monad's ability to "mirror" and hence multiply the universe from its own perspective. The monad, an obscure analogue of the totality of monads comprising the phenomenal world, expresses everything outside of itself.

The principle of expression, which solves the riddle of solipsistic perception, supplies as well a key to the logic of the open secret which characterizes the topology of nightlife. Siegfried Kracauer described Josef von Sternberg's film The Blue Angel, set in the Tingeltangel Club in Berlin, as an instance of "the appearance of lost inwardness"—a phrase that may be applied as well to the nightlife portrayed in the film (Kracauer 631). Strictly speaking, the appearance of "inwardness" in the external world—that is, the appearance of forms incommensurable with the "laws" of the visible world—is an impossible event, a contradiction that produces the intrinsic obscurity of nightlife (its location, its language, its social composition). As a form of inwardness, the nightspot appears in the world, though it seeks to erase, or obscure, any trace of that manifestation: it is an open secret, a productive paradox. And the dialectic of obscurity—Milton called the light of the underworld "darkness visible"—is precisely what aligns nightlife historically and conceptually with lyric poetry. For poetry as well may be described as "the appearance of lost inwardness," an impossible event yielding unmappable places and unreal combinations of social being. From the very beginning, we have known that Orpheus couldn't turn his back on the underworld and that by turning back he drew the gaze of those living in the upper world to the lyrical topos of the underworld. We have not sufficiently understood, however, that the underworld is at once a lyrical or metaphysical site and a historical place, even if the ambiguity of its material conditions cannot be isolated from the substance of poetry.