I. Being-with dysappears
Heidegger's account of being-with performs the same philosophical operation three times, at three increasingly consequential sites in Being and Time, and the operation is precise enough to name and test rather than merely describe. Call it conversion. A conversion occurs when a phenomenon is introduced into a philosophical architecture as ontologically irreducible, structurally distinct from anything the architecture has already secured, and is then, at the point where its positive content would have to be supplied, redescribed entirely in terms borrowed from a category the architecture already possesses, with no acknowledgment that a reduction has taken place and with the original vocabulary of irreducibility left standing undisturbed alongside the redescription. The word survives. The independence does not.
Section 26 of Being and Time performs the introduction. Dasein is declared, in Heidegger's strongest available terms, to be essentially being-with, Mitsein, equiprimordial with being-in-the-world and irreducible to it. What follows is not silence on the matter, and it is not denial, but conversion, performed three times: once when solicitude, Fürsorge, is asked to supply the lived content of being-with and instead supplies a structure oriented entirely around the other's own self-relation; once when das Man is introduced as the everyday mode of being-with and turns out, on Heidegger's own explicit description, to be an existential of the single Dasein rather than a relation to a second one; and once, finally and most consequentially, when death is specified by a set of formal predicates that exclude relationality from the concept by definition.
This diagnosis needs a standard against which to test it, and the standard should be stated before any textual argument begins, so that each conversion can be checked against it rather than asserted. A relation between two Dasein counts as genuinely irreducible to either equipmental coordination or to a single Dasein's relation to itself only if it satisfies four conditions together. First, it must involve two centers of disclosure: not one Dasein and an object, however complex, but two beings each capable of disclosing a world rather than merely being disclosed within one. Second, it must exhibit mutual unpredictability: neither party's next response can be derived in advance from the other's prior state, in the way a tool's behavior can be derived from its physical properties or a mood's unfolding can be derived from Dasein's own prior self-relation. Third, it must involve reciprocal interpretation: each party interprets the other's expressions and actions, and that interpretation feeds back into what each does next, rather than one party doing the interpreting while the other is merely interpreted. Fourth, it must be temporally evolving rather than fixed: the meaning of any given moment in the exchange is settled only retroactively, by what follows it, rather than determined in advance by a structure that precedes the exchange and governs it from outside.
These four conditions are not imported from outside Heidegger's own commitments. They follow directly from what section 26 itself claims: the equiprimordiality of Mitsein, the rejection of inference from a prior solitary ego, the insistence that the other is disclosed rather than merely encountered. If those claims are to mean what they say, the resulting phenomenon should satisfy all four. What follows tests each of the three conversions against them in sequence, before turning to the strongest available counterexamples, a sustained concrete case, and the secondary literature that has approached this problem without quite locating it. The essay closes by naming, only at that point, the broader theoretical framework within which the diagnosis can be generalized, and by proposing, more tentatively, that the same operation recurs beyond Mitsein, in Heidegger's treatment of language and history, and in the trajectory of his later work.
II. The Reflexive Core: Why Conversion Was Available
Before asking why Heidegger converts being-with into self-relation rather than, say, abandoning the concept altogether or leaving it genuinely open, it is worth asking what made self-relation available as a destination in the first place. The answer is given extremely early in the book, well before either the equipmental analysis or section 26, and it is given precisely enough to function as direct evidence rather than background context.
Dasein is introduced, in the methodological opening chapters, as the entity distinguished by Jemeinigkeit, mineness: the entity whose being is, in each case, its own, and for whom that being is itself an issue. This is the most basic determination of Dasein offered anywhere in the book, prior to the discussion of equipment in chapter three and prior, by a wide margin, to the discussion of being-with in chapter four. Before Dasein is ever shown coordinating with a hammer or encountering another Dasein, it has already been characterized, at the level of fundamental ontology, as a being structured by a relation to itself.
This determination is carried forward into the formal definition of care, Sorge, the structure Heidegger eventually presents as the unified meaning of Dasein's being as such. The formula is reflexive by construction:
»Sich-vorweg-schon-sein-in-(der Welt) als Sein-bei (innerweltlich begegnendem Seienden).«
Being-ahead-of-itself, sich vorweg, is the first and grammatically governing element of the formula, and it names a relation Dasein has to itself before it names anything else. Being-already-in-the-world and being-alongside entities encountered within the world are both folded into this prior, self-directed structure rather than standing independently of it. Care, the master-category from which Besorgen, concern for equipment, and Fürsorge, solicitude for others, are both subsequently derived as modifications, is reflexive at its root.
Equipmental coordination supplies the other category already secured by the time section 26 is reached, established in chapter three through the analysis of the tool in use, where Heidegger shows that the hammer's mode of being withdraws into the activity it serves rather than presenting itself as an object to be cognized:
»Je weniger das Hammerding nur begafft wird, je zugreifender es gebraucht wird, um so ursprünglicher wird das Verhältnis zu ihm, um so unverhüllter begegnet es als das, was es ist, als Zeug.«
This is non-recursive disclosure in its purest form, a mode that does not respond to being disclosed, and it matters here because it specifies, with the self-relational category just established, exactly what was available to Heidegger when he reached section 26 and needed to supply content for a phenomenon he had just declared irreducible to anything already on hand. Two categories were available. One was equipmental coordination. The other was self-relation, secured even earlier, at the level of Jemeinigkeit, and destined to be elaborated at enormous length across the rest of the book as the reflexive core of care itself. No third category had been built. When being-with needed cashing out, it could be cashed out as equipmental reference, as the later discussion of the workshop will show happens to collective coordination, or it could be cashed out as a modification of the self-relation already given pride of place in the definition of care, which is what happens to Fürsorge, das Man, and ultimately death. Conversion, on this reading, is not three separate interpretive choices requiring three separate explanations. It is a single structural fact, that self-relation was the only fully elaborated relational category Heidegger's architecture possessed, unfolding three times at three different points in the text.
III. The Promise: Section 26
Section 26 is the site of Heidegger's nearest approach to a phenomenon satisfying all four conditions, and it deserves to be read with the same care given to the equipmental analysis, because the promise it makes is unusually explicit. Heidegger does not merely mention others in passing. He stages the question of how Dasein relates to other Dasein as a structural question on a par with the question of how Dasein relates to equipment, and answers it by introducing a third existential, distinct from both.
»Die Welt des Daseins ist Mitwelt. Das In-Sein ist Mitsein mit Anderen. Das innerweltliche Ansichsein dieser ist Mitdasein.«
And more strongly still, a few pages later:
»Das Dasein ist wesenhaft Mitsein.«
These are not casual formulations. Wesenhaft, essentially, is Heidegger's strongest available term of ontological commitment. Being-with is not something that happens to Dasein under certain circumstances, when other people happen to be nearby. It is constitutive of what Dasein is, equiprimordial, gleichursprünglich, with being-in-the-world itself. Heidegger goes further, and this is the move that should be weighed most heavily by anyone inclined to read section 26 as a minor or merely formal gesture: he explicitly rejects the dominant philosophical solution to the problem of other minds, the inference from one's own case by analogy, Einfühlung. The other is not reached by inference from an originally solitary ego outward to other egos inferred to exist. Mitsein is not a conclusion Dasein draws. It is, on Heidegger's own account, already operative in the structure of being-in-the-world before any such inference could be attempted, and it remains operative even in a Dasein's factical absence from other people, since being-with is an existential structure of Dasein as such and not merely an ontic fact about who happens to be in the room.
If this commitment were carried through, the resulting phenomenon would have to satisfy all four conditions stated at the outset: two centers of disclosure, since the other is explicitly said to disclose rather than merely be disclosed; mutual unpredictability and reciprocal interpretation, since the relation is denied to be a construction out of a prior solitary ego's inferences; and temporally evolving structure, since nothing in section 26 suggests the relation is settled in advance by a fixed framework. Section 26 promises all four. The question the rest of the existential analytic has to answer is which of them survive contact with the text that follows.
IV. Conversion One: Fürsorge
The existential meant to carry the content of Mitsein into the texture of everyday life is Fürsorge, solicitude, derived, like Besorgen, as a modification of care. The derivation matters more than commentary on Fürsorge usually allows it to. Sorge für, care for, retains the grammatical structure of the master-formula examined above: one term directs itself toward another, asymmetrically, the way being-ahead-of-itself directs itself toward the entity Dasein is to become. Fürsorge is built, from its very name, as a relation one party has toward another, not a relation two parties have toward each other simultaneously. This is worth stating before any of its specific content is examined, because it means the first condition, two centers of disclosure each contributing to the relation, is placed under strain by the concept's grammar before a single sentence of phenomenological description has been written. A vocabulary built around für, for, does not by itself rule out reciprocity, but it does not supply it either, and everything that follows shows that Heidegger never supplies it from elsewhere.
Heidegger distinguishes two extreme modes. Einspringende Fürsorge, leaping-in solicitude, takes over the other's care for them, substitutes itself for what the other would have had to do, and in doing so can dominate and render the other dependent, a relation of subjection in which the one cared for becomes governed by the one caring. This mode fails the four conditions in the most direct way available: it collapses the second party into something closer to an object of management than a second center of disclosure, the very asymmetry Heidegger's own description identifies as a danger.
Vorausspringend-befreiende Fürsorge, leaping-ahead solicitude, is offered as the corrective, and it is worth taking seriously exactly because it is the mode Heidegger marks as authentic. It does not take the other's care away. It helps the other see that care and take it up as their own. But examine what this requires structurally. The one who leaps ahead must already see, in some sense, what the one who is helped does not yet see, which means the structure presupposes an asymmetry of position, one party oriented toward a destination, the other to be brought toward it, even when the content of that destination is formally specified as nothing more than the other's own ownmost potentiality-for-being. Score this against the four conditions directly. Two centers of disclosure: only weakly satisfied, since the relation is described entirely from the side of the one who leaps ahead, with the other's contribution registered as the target of an action rather than as a second source of initiative. Mutual unpredictability: absent by construction, since the leaping-ahead party's orientation is fixed in advance, toward the other's self-relation, regardless of what the other might actually do or say in response. Reciprocal interpretation: absent, since nothing in the description requires the leaping-ahead party's own understanding to be revised by what the other contributes. Temporally evolving adjustment: absent, since the structure specifies an endpoint, the other's return to their own potentiality-for-being, that the process is meant to reach, rather than a sequence whose meaning stays open until it closes.
This explains why every relation Heidegger is willing to call authentic terminates in a better relation to oneself. It is not an oversight repeated by coincidence at each site, but what the concept of Fürsorge, derived from a reflexively defined Sorge and built grammatically around für rather than mit, was always going to deliver once its content was specified. A vocabulary descended from sich vorweg cannot, without some independent supplementation Heidegger never provides, produce a structure in which two parties simultaneously direct themselves toward each other rather than one directing itself toward the other's self-directedness.
The gap is thrown into relief by a resource Heidegger had available and did not use. Aristotle, whom Heidegger draws on extensively elsewhere in the existential analytic, including the account of phronesis that shapes the treatment of practical understanding, devotes two full books of the Nicomachean Ethics to philia, friendship, because friendship cannot be analyzed as one party's solicitude directed at another. Aristotelian friendship is constitutively symmetrical: each friend wishes the other well for the other's own sake, and each friend's character is, in the developed case, genuinely responsive to and partly constituted by the other's, in a way neither could specify in advance or achieve alone. Nothing in Heidegger's vocabulary for solicitude, in either of its two modes, has a place for this symmetry, because the vocabulary is built, at the level of grammar, around a single direction of address. Pedagogy turns out to be the sharpest test case, examined below in a concrete instance, because teaching looks, on the surface, like exactly the kind of relation vorausspringende Fürsorge is meant to describe, one party already further along, helping another toward their own understanding, and yet, as that instance will show, real teaching routinely produces outcomes the formal structure has no way to accommodate.
V. Conversion Two: Das Man
If Fürsorge narrows the promise, das Man closes it, and it is here that the mechanism can be specified with the most textual confidence, because Heidegger states it almost in so many words. Heidegger's account of everyday being-with is organised entirely around the anonymous, averaged subject he calls das Man, the they. The they is not a group of other people. It is, on Heidegger's own formulation, a way Dasein relates to itself.
»Jeder ist der Andere und Keiner er selbst.«
This single sentence makes the failure of the first condition explicit rather than merely apparent. Das Man names a condition in which everyone has become the other and no one is themself, which means that whatever das Man is, it is not, structurally, a second center of disclosure standing over against the first. It is what happens to a single Dasein's relation to itself when that relation is governed by an internalised, averaged standard, borrowed from no one in particular, rather than owned as Dasein's own. Heidegger confirms the categorial status directly:
»Das Man ist ein Existenzial.«
An existential, in Heidegger's vocabulary, is a structure of Dasein's own being, not a feature of the world external to Dasein and not a description of other people considered as objects of address. Das Man is something Dasein is, not someone Dasein meets. Score it against the four conditions and the result is not partial failure but categorial disqualification on the first condition alone, since the entire apparatus is explicitly positioned, by Heidegger's own terminology, on the side of the single Dasein's own existential structure rather than on the side of a second locus of disclosure. The remaining three conditions cannot even be meaningfully tested, because there is no second party in the picture for them to apply to.
This is the precise point at which the promise of section 26 is converted rather than abandoned. Heidegger does not say that others do not matter, or that being-with is unreal. He keeps the word. What he does is relocate everything that follows from the word into Dasein's relation to itself. Gerede, idle talk, Neugier, curiosity, Zweideutigkeit, ambiguity, the characteristics that fill out the phenomenology of everyday das Man across the sections that follow, are each, on inspection, descriptions of how a single Dasein's understanding, language, and orientation are structured by an averaged standard, not descriptions of an encounter between two parties who read, anticipate, conceal from, and adjust to each other. There is no scene anywhere in this material, comparable to the equipmental analysis or the later analysis of anxiety, in which two Dasein are shown actually responding to each other as an exchange unfolds, each one's next move shaped by an interpretation of the other's last move that neither could have specified in advance. The dyad never appears. What appears instead, repeatedly and at length, is the structure of a single Dasein's relation to a standard it has absorbed.
Heidegger himself supplies a disclaimer at exactly the point where the conversion is performed, and the disclaimer is worth examining for what it reveals about his own awareness of the difficulty. He insists, introducing Verfallenheit, falling, that the term carries no negative ontic valuation, that falling is not a fall from some purer prior state, that it names a structural and permanent feature of everyday Dasein rather than a contingent failing to be regretted. The disclaimer is sincere and unconvincing in roughly equal measure, and the reason it is unconvincing is precise rather than merely a matter of tone. Gerede, Neugier, Zweideutigkeit are not neutrally named. Each is defined by what it fails to achieve relative to genuine disclosure, understanding, and resoluteness, the very terms reserved elsewhere in the text for authentic self-relation. A vocabulary that consistently measures one structure against the standard proper to a different structure cannot remain neutral about the first structure no matter how firmly its author insists otherwise in a parenthetical aside.
What has actually happened can now be stated with precision, and this is the conflation underneath the conversion at this site. Heidegger never separates two questions that are logically independent of each other. The first question is structural: is being-with, as such, an irreducible existential, equiprimordial with being-in-the-world, distinct from both equipmental coordination and self-relation. Heidegger answers this question affirmatively, explicitly, and at length in section 26. The second question is contingent: does the particular, historically and culturally specific form that average, public, levelled discourse happens to take in Heidegger's own description amount to a structural failure of being-with itself, or merely to one degraded mode among others that being-with might take. Heidegger never asks this second question separately from the first, because he has no apparatus for distinguishing a type from a token. The contingent material, das Man's particular leveling, gets treated as though it exhausted the structural feature it was supposed to be one instance of. The slot opened in section 26 stays formally occupied, the word survives, the citation survives, the equiprimordiality survives as a claim one can quote, but the question of what a non-degraded, genuinely interpersonal mode of being-with would consist in is never separately asked at all. It is foreclosed by the same move that condemns das Man, before it could ever have been raised.
VI. Conversion Three: Death
If the conversion at das Man left any ambiguity about whether the promised phenomenon might be recovered elsewhere in the architecture, the existential analytic of death removes it, and removes it by definitional fiat rather than by accumulated description, which makes it the cleanest test of the four conditions in the entire book. Death is specified, in the formal sketch that opens the analysis, by a small set of existential characteristics, and one of them does the decisive work. Death is Dasein's eigenste Möglichkeit, ownmost possibility, the possibility most properly its own and no one else's. It is gewiss, certain, and as such unbestimmt, indefinite as to its when. And it is, crucially, unbezüglich: non-relational. No one can die my death for me, in the sense that matters existentially. Another may die in my place in the ontic sense of dying so that I might live, but no one can take over my dying as the structural event that individualises me as the Dasein I am.
Apply the four conditions and the result is total failure by stipulation rather than by interpretive drift. Two centers of disclosure: explicitly excluded, since unbezüglich names the absence of any relational structure at all, not merely its weakness. Mutual unpredictability, reciprocal interpretation, and temporally evolving adjustment all presuppose a second party whose contribution to the structure is, by the predicate's own content, ruled out before any of them could be tested. This is the only one of the three conversions that operates by definition rather than by phenomenological description drifting away from its formal premise, which is what makes it the sealing move rather than merely a third instance. Fürsorge narrowed the promise through what it failed to supply. Das Man closed it through a categorial misdescription Heidegger himself states plainly. Death forecloses it by writing the exclusion into the constitutive predicates of the one structure everything else in the existential analytic is organized to reach.
The call of conscience that summons Dasein toward this possibility calls Dasein away from das Man and toward itself alone, silently, with no content other than the bare summons to take up one's ownmost potentiality-for-being. Authenticity, Eigentlichkeit, ownedness, is achieved at exactly the point where relation to others has been stripped away as a matter of definition rather than merely as a matter of emphasis. What began in section 26 as a structural promise of an irreducible third phenomenon is sealed, by the time the analytic reaches its center of gravity, into a single relational predicate, unbezüglich, that names the explicit exclusion of that phenomenon.
VII. Two Terms, Not Three
The result of this sequence can now be stated as a single architectural fact about Being and Time, and it is sharper than the usual charge that Heidegger neglects others. The book does not, in the end, operate with three types of disclosure inadequately related to one another; it operates with two, dressed as a dualism between authenticity and inauthenticity, when both terms of that dualism are in fact the same type, self-relation, distinguished only by whether the standard governing it is owned, eigentlich, or borrowed, das Man, uneigentlich. Inauthentic Dasein relates to itself through an averaged standard absorbed from no one in particular. Authentic Dasein relates to itself through the call of conscience, which has no content beyond the bare summons back to one's ownmost self, away from that averaged standard. Both are loops internal to a single Dasein. Neither is a relation between two parties who read, anticipate, conceal from, and adjust to each other under conditions neither controls. The phenomenon promised by name in section 26 does not survive as a live third term anywhere in the finished architecture of the existential analytic. It survives only as a word, Mitsein, attached to a content that was converted into something else at every site where it could have been filled in.
This is also why authenticity and inauthenticity feel, on a careful reading, less like two genuinely different relations to others and more like two postures of the same solitary structure toward an internalised crowd. Heidegger's own vocabulary licenses exactly this description without intending to. Both das Man and the call of conscience are, in his own terms, existentials, structures Dasein has rather than encounters Dasein undergoes with a second center of disclosure.
VIII. The Strongest Counterexamples
If the argument so far is correct, a sceptical reader will reasonably ask where else in Being and Time a phenomenon satisfying all four conditions might be thought to survive, outside the three sites already tested. A fourth candidate, friendship, has already been addressed above: Aristotle's philia was available to Heidegger as a resource for a constitutively symmetrical relation, and its absence from the existential analytic, despite Heidegger's extensive use of Aristotle elsewhere, is consistent with everything traced so far. Three further candidates deserve serious attention in their own right: language, historical community, and, the strongest of the three by a clear margin, shared practical work.
Discourse, Rede, is named in section 34 as one of three equally fundamental existentials constituting the disclosedness of being-in-the-world, alongside understanding and attunement, and Heidegger explicitly lists Mitteilung, communication, among its constitutive moments. This looks, at first glance, like exactly the site where two Dasein might be shown exchanging meaning under conditions of genuine mutual unpredictability. The promise is no better kept here than at Mitsein itself. Mitteilung receives barely a paragraph of development before the chapter turns, for the rest of its length, to Hören, listening, and Schweigen, keeping silent, treated almost entirely as structures of Dasein's own receptivity and self-possession, and then to Gerede, which converts discourse into exactly the same self-relational material das Man supplies for sociality generally. Heidegger names Mitteilung. He never phenomenologically develops what happens between two speakers who do not yet know what the other will say next, who shape their next utterance around an interpretation of the last one.
The most serious textual candidate is historicality. In the second half of Division II, Heidegger introduces Geschick, communal destiny, as distinct from Schicksal, the individual Dasein's own fate, and ties it explicitly to a Volk, a generation, and a shared heritage, Erbe, handed down and taken up in Mitsein and Mitwelt. This is the one moment in the book where Heidegger gestures at something larger than a single Dasein or a dyad, and the chapter's proximity to commitments Heidegger would make explicit the following year is a matter for the historical literature rather than this essay. The structural point holds independently of that history. Examined on its own terms rather than its rhetoric, Geschick does not describe several Dasein reading and adjusting to one another as events unfold. It describes many individual Dasein, each independently resolute, each appropriating the same handed-down possibility through an act of resoluteness that remains, by Heidegger's own definition in the preceding chapters, a structure of that Dasein's relation to its own ownmost potentiality. Communal destiny is parallel self-relation, many individual loops oriented toward a shared content, rather than a single structure running between them.
Shared practical work is the candidate that deserves to be taken most seriously, and it is worth granting its force before showing how the text forecloses it, because the phenomenon itself is genuinely promising in a way the other candidates are not. Several Dasein coordinating within a single workshop, a kitchen, a surgical team, do not obviously fail the four conditions the way das Man does. Two centers of disclosure are plainly present, since each worker discloses a world rather than merely figuring within one. Mutual unpredictability and reciprocal interpretation are at least plausible candidates for what coordinated collective work actually requires, since a co-worker's next move is rarely fully derivable in advance, and skilled collaborators do read and adjust to each other's actions as work proceeds. If the promised phenomenon survives anywhere in the equipmental world Heidegger describes so well, this looks like where to find it.
The text forecloses it nonetheless, and the mechanism is worth tracing in the same detail given to Fürsorge and das Man, because it is a different mechanism from either. Heidegger's own development of the work-world explicitly brings other people into the analysis, but only as moments within the equipmental referential totality rather than as second centers of disclosure encountered in their own right. The shoemaker's leather refers to the tanner, the finished shoe refers to the customer for whom it is made, and the customer, on Heidegger's own description, is encountered in the equipment itself, as part of what the equipment is for, before any question of reading or being read by that customer as a second locus of disclosure arises. The same structure governs every other person who appears in the discussion of the work-world: each is introduced as a term within the referential nexus of in-order-to and for-the-sake-of-which, not as a party whose own unpredictable contribution the analysis tracks. This is conversion of a different kind from the one performed on Fürsorge and das Man. Those two convert being-with into self-relation, the second of the two categories already available to Heidegger's architecture. Collective coordinated work converts being-with into equipmental reference, the first of the two categories, secured even earlier and even more completely. The direction of conversion differs depending on which aspect of being-with is under discussion, dyadic and individuating in one case, collective and work-embedded in the other, but the underlying operation is identical: a phenomenon introduced as irreducible is redescribed in terms of a category the architecture had already finished building, with no acknowledgment that anything has been lost in the redescription.
What this shows, taken together with the two prior conversions, is that Heidegger's text has exactly two directions available for converting being-with, and uses both, depending on context. Where being-with threatens to individuate, in solicitude, in everydayness, in death, it is converted into self-relation. Where being-with threatens to appear as collective coordination among several parties at once, in the work-world, it is converted into equipmental reference. The promised phenomenon is excluded from both directions, not because Heidegger argues against it, but because his architecture, at the moment each aspect of being-with needs cashing out, has only ever built the other two. None of the four candidates examined here, then, supplies what section 26 promised, and three of them fail in distinct ways worth holding apart: language is underdeveloped relative to its own formal introduction, granted a name and abandoned; historical community is parallelized, multiplied into many loops rather than coupled into one; and shared practical work, despite being the strongest candidate on its face, is absorbed into equipmental reference through a mechanism as precise and traceable as the one governing Fürsorge and das Man.
IX. A Concrete Case: Teaching in Moses Hall
The clearest way to see what the architecture is missing is not further textual analysis but a single example of the kind of encounter vorausspringende Fürsorge claims to describe, examined against the four conditions stated at the outset rather than left as an impressionistic illustration. The example is autobiographical, and it concerns the relation Fürsorge is meant to cover: a teacher's solicitude for a student's own coming-to-understand.
My first sustained engagement with Heidegger's account of being-with took the form of a one-semester independent study at Berkeley, an arrangement consisting of weekly one-to-one conversations in Hubert Dreyfus's office in Moses Hall. Nothing about the structure of those meetings was scripted in advance. Each week I arrived with a reading and a set of half-formed claims about what Heidegger's being-with actually was, and each week Dreyfus responded in ways I could not have predicted from the week before, sometimes redirecting the argument entirely, sometimes pressing a single sentence until it gave way, sometimes simply disagreeing in a manner that forced the next week's preparation to start from a different place than I had planned. I could not know in advance what he would make of a given claim, and the shape of each subsequent week's thinking depended on a reading of his response that he had not specified and that I could not derive from any general theory of what Dreyfus, as a Heideggerian, was supposed to think.
Score the encounter against the four conditions directly, since that is the standard the rest of this essay has used throughout. Two centers of disclosure: satisfied without qualification, since both parties were engaged in genuine philosophical work, each capable of producing a reading the other had not anticipated. Mutual unpredictability: satisfied, since neither party's contribution in a given week was derivable from the prior week's exchange. Reciprocal interpretation: satisfied, since each week's preparation was shaped by an interpretation of what had happened the week before, an interpretation itself revisable by what happened next. Temporally evolving adjustment: satisfied most clearly of all, since the meaning of any given week's exchange was settled only retroactively, by the direction the following weeks took, and was not fixed in advance by either party's prior position.
The independent study concluded with a final paper whose argument Dreyfus did not accept. The paper argued that Heidegger's account of being-with in Being and Time cannot be assimilated to the kind of shared, practical, background coping that Dreyfus's own reading of Heidegger had made central, that Mitsein names something the pragmatist interpretation could not actually accommodate within its own framework. Dreyfus disagreed with the conclusion. That disagreement is itself part of the phenomenon under discussion, not an incidental detail. A relation in which the senior party could simply have absorbed the junior party's claim into a pre-existing framework, or set it aside without engaging its specifics, would have been closer to einspringende Fürsorge, leaping in and taking over. What happened instead was genuine friction between two positions that remained, at the end of the semester, still distinct, arrived at through a process neither party could have run alone or predicted in advance. Vorausspringende Fürsorge, on Heidegger's own formal description, aims to return the other to their own ownmost potentiality-for-being. It has no category for a disagreement that survives the encounter intact, because surviving disagreement implies that both parties remain, throughout, unpredictable enough to each other to produce an outcome that is not simply one party's self-relation extended into the other.
The philosophical point can now be stated fully rather than merely illustrated. Dreyfus's own reading of Heidegger treats das Man and the shared background of practices as the positive condition of all intelligible coping, and on that reading, what happened across the semester should be explicable as two participants drawing on a shared disciplinary background, the norms of Heidegger scholarship, the conventions of philosophical argument, that made our exchanges intelligible to each other. The background reading explains a great deal. It explains why we could understand each other's claims at all, why a sentence about Zuhandenheit meant roughly the same thing to both of us, why disagreement was even possible rather than merely confused. What the background reading cannot explain is the specific content of any given week's redirection, or the specific shape of the disagreement that survived the semester, because a shared background, however rich, is by definition the same resource available to both parties before the exchange begins, and cannot by itself generate the particular, unpredictable, person-specific responses that actually occurred. Dreyfus could have responded to a given week's argument in any number of ways consistent with the same shared background of Heideggerian scholarship. That he responded in the specific way he did, and that his specific response was itself shaped by what I had said the week before in a way neither of us could have derived from the background alone, is exactly the surplus the background reading cannot capture and exactly what the four conditions are designed to register. Background coping explains the possibility of mutual intelligibility. It does not explain, and on its own terms cannot explain, the actual, particular, two-way process by which that intelligibility was produced and revised across a semester.
X. The Secondary Literature: Six Ways of Missing the Mechanism
Heidegger's monologism has been named before, and named by readers as careful as any in the tradition, but no prior reading, sympathetic or critical, locates the mechanism traced here: the specific, repeatable conversion operation, its grounding in the reflexive structure of Sorge, and its two available directions, into self-relation and into equipmental reference. It is worth being precise about why six distinct and substantial bodies of work, taken together, do not anticipate this argument, because the reasons differ from reading to reading and the differences are themselves instructive.
Levinas offers the most developed alternative, and it deserves more credit than a brief mention usually grants it. He does not merely observe that Heidegger neglects the other and propose, by way of correction, a change of philosophical priority. He builds an independent positive phenomenology of alterity: the face, le visage, resists being absorbed into the totalizing structures of the Same, le Même, because the Other, Autrui, presents an excess that no act of comprehension can close. This is a genuine, substantial account of an irreducible relation between two centers, not merely an inversion of ontology and ethics asserted by fiat. But the project Levinas builds is a rival first philosophy, constructed from a different starting point than Heidegger's own text, rather than an internal diagnosis of how Heidegger's specific architecture, on its own terms, performs a reduction. Levinas's apparatus explains why totalization of the Other is a philosophical error in general. It does not predict, and is not built to predict, that the error will occur specifically at Fürsorge, through the asymmetric grammar of Sorge für, specifically again at das Man through an explicit existential reclassification, and specifically a third time at death through a stipulated relational predicate. The four conditions used throughout this essay, and the location of their failure in identifiable sentences, are not available from within Levinas's framework, because his target is the totalizing structure of ontology as such, not a typology of disclosure that could distinguish equipmental, self-relational, and interpersonal modes from one another in the first place.
Theunissen, in a study devoted entirely to the question of the other in modern philosophy, comes closer to the textual mechanism than Levinas does, arguing that Heidegger never gets beyond a merely negative Mitsein, an acknowledgment of others that falls short of a genuine encounter with a Thou. This is, in substance, an early sighting of the same gap. But Theunissen's own vocabulary, drawn from the dialogical tradition of Buber, has no resources for explaining why the gap opens specifically at Fürsorge and das Man rather than elsewhere, or for tracing it forward to its sealing in the unbezüglich of death, or for explaining, as the reflexive Sorge formula does, why self-relation rather than some other category was the destination of the reduction.
Bernasconi extends the ethical line of critique that Levinas opens, with particular attention to how Heidegger's structural inability to accommodate genuine alterity connects to the concrete failures of Heidegger's own political and historical conduct. This work matters and should not be set aside, but it operates, like Levinas's, primarily at the level of ethical and political consequence rather than at the level of a traceable textual mechanism internal to the existential analytic's own categories.
Nancy comes closest of all six, and deserves the most serious engagement. Being Singular Plural takes Mitsein to be Heidegger's most important and most underdeveloped concept, and proposes to rebuild ontology around it: being is originally plural, comparution, co-appearance, rather than a solitary structure to which plurality is added afterward. This is, in its ambition, a direct response to the gap this essay identifies. But Nancy's response is to displace the architecture rather than to diagnose it. Where this essay locates a specific, repeatable operation within Heidegger's existing categories and traces its grounding to a specific formal feature of the existing text, Nancy proposes a new starting point that dissolves the priority of solitary Dasein altogether. The cost of that solution is that it has no way to mark what is actually missing as missing. If plurality is originary, there is no longer a contrast between a category that was secured, self-relation, and a category that was promised and converted, being-with, because both have been folded into a single undifferentiated origin. Nancy senses the wound accurately and treats it by erasing the distinction whose erosion caused it.
Guignon and Carman represent a different failure mode, closer to the inverse of Nancy's. Both have argued, against readings that find Heidegger asocial, that Dasein's understanding is essentially shared and public, embedded in a world of common practices and norms from the outset, and that authenticity does not require withdrawal from this shared world but only a different relation to it. This is, in effect, the philosophical defense of the same move the discussion of shared practical work above identifies in the text itself: being-with rehabilitated by assimilation to the non-recursive background of practices, the second of the two directions conversion can take. Guignon and Carman are right that Heidegger's social world is richer than a purely individualist reading allows. They are not positioned to notice that this richness is itself a conversion, because their reading does not distinguish a shared background that does not respond to being read from a second party who does.
Blattner's absence from the standard charge of monologism is itself a data point. His work on temporality and death, among the most rigorous treatments these chapters have received, proceeds through exactly the material examined in the conversion at death without registering being-with as a live problem at all. This is not a criticism of the scholarship, which is careful and precise on its own terms; it illustrates instead how invisible the gap has been even to commentators reading the most relevant chapters with great care, since nothing in the standard apparatus of Heidegger scholarship flags a missing third category as a missing third category.
Lafont arrives at a structurally adjacent conclusion from an entirely different direction, concerned not with sociality but with truth and the possibility of correction. Her sustained critique of Heidegger's holism about world-disclosure argues that, because Dasein's understanding of entities is disclosed as a whole prior to any particular encounter, that understanding cannot, on Heidegger's own terms, be genuinely revised through an encounter with evidence or with another's perspective that the prior disclosure has not already made room for. This is an independent confirmation, arrived at through epistemology rather than through the analysis of Fürsorge or das Man, of exactly the failure the third and fourth conditions name: if disclosedness cannot be revised by what is encountered within it, reciprocal interpretation and temporally evolving adjustment are blocked at the most fundamental level, before the question of other people is even raised. Lafont's critique and this essay's diagnosis converge from opposite directions on the same architectural fact, which is itself evidence that the fact is real rather than an artifact of either approach.
Dreyfus, finally, returns the discussion to where it began. The pragmatist reading he inaugurated does not diagnose a monologism in Heidegger at all, because it does not treat Mitsein as a problem requiring diagnosis in the first place. Das Man and the shared background of practices are rehabilitated as the positive condition of all intelligible coping rather than as Heidegger's own fallen mode, and this rehabilitation has genuine textual warrant, as the discussion of the shoemaker and the work-world above shows: Heidegger's own text already converts collective coordination into equipmental reference, and Dreyfus's reading extends that conversion rather than inventing it. What the pragmatist reading does not do, and cannot do from within its own resources, is notice that the same text performs a second, different conversion, into self-relation rather than equipmental background, at Fürsorge, at das Man's existential status, and at death. This is also why a paper arguing that Heidegger's being-with resists assimilation to pragmatist coping met with genuine, substantive disagreement rather than easy assent in Moses Hall. The disagreement was not a misunderstanding to be cleared up but a real fault line between two readings of Heidegger, neither of which, on its own terms, had identified the conceptual apparatus this essay uses to adjudicate between them.
XI. Naming What Has Been Found
Everything argued to this point has been argued in Heidegger's own vocabulary and in general terms available to any reader regardless of theoretical commitment: conversion, the four conditions, the reflexive grammar of Sorge, the two available directions of reduction. This is deliberate. The diagnosis should stand or fall on the textual evidence, not on the prior acceptance of an external framework.
It is nonetheless worth noting, now that the diagnosis is complete, that the three categories used throughout, equipmental disclosure that does not respond to being disclosed, self-relational disclosure in which an agent responds to its own states, and the interpersonal disclosure the four conditions were built to test for, correspond exactly to the typology of non-recursive, self-recursive, and interrecursive domains developed independently within Living Value Theory. The correspondence is worth registering for what it suggests rather than for what it proves: a typology developed for entirely different purposes, addressing economics, social regulation, and the structure of modern institutions, turns out to map without remainder onto the categories a sufficiently close reading of Being and Time generates on its own. That convergence is some evidence that the typology tracks a real structural distinction in the phenomena themselves, rather than an interpretive grid imposed on Heidegger from outside. Heidegger names the first category with precision in the equipmental analysis. He elaborates the second, self-relation, at greater length and depth than any other phenomenon in the book. He reaches for the third, once, explicitly, in section 26, and then converts it back into the second, twice, before sealing the exclusion into the very definition of authentic selfhood.
It is also worth asking, briefly, why a vocabulary for the third category was unavailable not only to Heidegger but to the philosophical tradition he inherited and to most of the tradition that followed him. The inherited vocabulary was built for two jobs. The first, descending from Descartes and elaborated across the early modern period, was distinguishing subjects from objects. The second, descending from German idealism and elaborated across the nineteenth and twentieth centuries in increasingly sophisticated form, was characterizing what a subject's relation to itself could be: mood, reflection, conscience, narrative identity, self-interpretation. What this inheritance never required, and so never built, was a vocabulary for the relation between two such subjects considered as a structure in its own right, irreducible to either side taken alone. Heidegger had every resource available to notice this gap, more than any predecessor, because his own method required him to ask what kind of being a relation could have before asking what content to give it. That he asked the question, in section 26, and then filled the answer with material drawn from a category he had already finished building, is the clearest available record of how complete that inheritance's blind spot was.
XII. Coda: Conversion as a General Operation
This essay has confined its central claims to a single, well-evidenced site: the treatment of being-with across Being and Time, traced through three conversions, tested against the strongest counterexamples, and confirmed by a concrete case and a survey of the secondary literature. A further question, raised but not settled here, is whether conversion is specific to Mitsein or whether it names a more general operation recurring across Heidegger's corpus. The evidence already gathered above offers some support for the broader claim without establishing it. The treatment of discourse in section 34 converts Mitteilung into the same self-relational material das Man supplies for sociality generally, before the chapter's content is exhausted by Hören and Schweigen, structures of Dasein's own receptivity. The treatment of historicality converts Geschick into parallel self-relation, many individual resolutenesses oriented toward a shared content rather than a structure coupling them. Both are conversions in exactly the sense defined at the outset, occurring well outside the chapters this essay has examined in detail.
If the operation recurs this readily once one knows to look for it, a further, more speculative possibility presents itself, offered here as a conjecture for a separate study rather than as a conclusion this essay has earned the right to assert. The trajectory of Heidegger's later work, the turn from the willing subject of resoluteness toward Gelassenheit, releasement, a listening rather than a grasping relation to Being, and the turn from disclosure as Dasein's achievement toward disclosure as something Being grants or withholds, would, if it followed the same pattern, represent a third application of the operation, this time converting Dasein's relation to Being into something resembling the non-recursive disclosure already secured for equipment in Division I, Being sending and withdrawing much as the hammer simply is what it is, rather than entering into the kind of mutually responsive relation the four conditions describe. Testing this conjecture properly would require the same standard of evidence applied here to Mitsein, tracing specific passages in the later writings against the same four conditions, and engaging the substantial secondary literature on the Kehre with the same care given above to the literature on being-with. That work remains to be done. What can be said now is only that the operation identified in Being and Time is not obviously confined to the chapters on being-with, and that a fuller account of Heidegger's corpus through the lens of conversion is a project this essay opens rather than completes.
XIII. Conclusion
Section 26 represents not an abandoned insight but a discovery for which Heidegger's architecture, at the moment the discovery was made, lacked the conceptual means of preservation. Self-relation had already been built, from the opening characterization of Dasein as Jemeinigkeit through the reflexive formula of care itself, into the most basic resource the existential analytic possessed. Equipmental disclosure had already been built, with comparable precision, in the analysis of the work-world. Being-with had neither, and so, three times in succession, in solicitude, in everydayness, and in death, and at least twice more, in discourse and in historicality, it was redescribed in terms of whichever already-finished category lay nearest.
Once the conversion mechanism is recognised, the architecture of Being and Time appears in a new light, not as a text that neglects the other but as a text that names the other correctly, once, with full ontological seriousness, and then cannot stop translating that naming back into a vocabulary built for something else. The history of Heidegger scholarship has largely debated whether this happened, weighing the charge of monologism against readings that defend Heidegger's sociality or relocate the problem to ethics or to a different ontology altogether. The more important question is how it happened. This essay has argued that the answer lies in a single recurring operation of conceptual conversion, traceable to a specific feature of Heidegger's own foundational categories, testable against an explicit standard, and visible, in the end, not only in the texts Heidegger wrote but in the rooms, Moses Hall among them, where his readers tried, and still try, to think the relation his own architecture could name but never quite hold.