Buoyant Ontologies: The Roots and Ramifications of Dialogue in Buber and Heidegger

Both Buber and Heidegger develop a notion of responsivity—in terms of dialogue regarding the former, and correspondence in the case of the latter—not merely as different types of discourse, but as transcendental structures in a relational or fundamental ontology. However, the responsive register is also transmitted on a different frequency; one that begins from elsewhere, not in a transcendental a priori, but in a transcendent address. Through a focused reading of Buber and Heidegger, I argue that responsivity not only takes place across the transcendental–transcendent divide, but shapes the ontological makeup of such a divide. In short, the ontological conditions of dialogue are negotiated, in turn, through dialogue.


Introduction
In Being and Time (1927), the question concerning the meaning of being is framed within the horizon of transcendental philosophy. In a certain sense, the project is nothing but a preparation, a "prolegomenon" for a possible ontology of human existence, by outlining the formal existential totality of the ontological structural whole of Dasein (Die formal existenziale Ganzheit des ontologischen Strukturganzen des Daseins) (Heidegger [1927(Heidegger [ ] 19961977a, p. 256). The project aims to provide an analysis of existentiality (Existenzialität), i.e., the coherent structure of that which constitutes existence rather than existence (Existenz) as lived life, because the former amounts to the (fundamental) ontology of Dasein, while the latter is parked as an ontic matter (eine ontische Angelegenheit) of Dasein (Heidegger [1927(Heidegger [ ] 19961977a, p. 17).
Such a formal account of the constitution of human existence has raised some critical objections. For example, the absence of "love" in Being and Time has been critically addressed by figures such as W. Koepps, Karl Jaspers, Ludwig Binswanger and Karl Löwith (see Agamben 1999, p. 185). The "ethical gap" in Heidegger's philosophy has been pointed out, and taken up, by thinkers such as Hans Jonas, Hannah Arendt, Jean-Paul Sartre and Iris Murdoch, among others. In Being and Time, "speech" (Rede) counted one of three equiprimordial existentials (Existenzialien) among attunement (Befindlichkeit) and understanding (Verstehen), while in the later writings, "language" grows into a significant thematic issue of its own, as the very foundation of the human being as such (Heidegger 1971, p. 112;1985, p. 230). While it is disputable whether Heidegger still operates within the framework of transcendental philosophy at this time (1959) (see Crowell and Malpas 2007), language is no longer conceived as a condition of human existence, in terms of the capacity for speech. Rather, language itself is said to speak: "language speaks" (die Sprache spricht) (Heidegger 1971, p. 124;1985, p. 243). As Martin Buber critically remarked, when stripped of the actual context of interlocutors, language risks ending up as a monologue, neglecting the intersubjective, or existentiell, dimension of the spoken word (see Mendes-Flohr 2014, p. 19). Buber himself is not blind to the ontological level; however, it is not conceived in terms of a formal structure, but located in spirit-that is, in the between I and thou.
Buber's I-Thou relation and Heidegger's existence-in-the-world are so constructed as to wrench philosophy from what they deemed to be its myopic focus on the isolated subject of cognition. And both ultimately turn to language, or more precisely the speech act as the fulcrum liberating thought from its solipsistic subject-centeredness.
This ambition to wrest the subject from potential solipsism is quite clear in Heidegger's conviction of the problem of the external world as a pseudo problem. The scandal of philosophy is not, as Kant proclaimed, that any such proof of the existence of the external world has failed, but that such proofs are attempted and expected again and again (Heidegger [1927(Heidegger [ ] 19961977a, p. 272). The problem of the external world and the problem of "other people" are both eliminated in one stroke by Heidegger's fundamental constitution (Grundverfassung) of Dasein as being-in-the-world, which, equiprimordially, is also already a "being-with (others)" (Mitsein). On the one hand, the skeptical question about the reality of the external world, and the solipsistic doubt about the existence of other people, already presupposes a shared transcendental horizon of meaning, in which such questions can be raised. Hence, the question has been answered by default. On the other hand, one might question this "numerological" move of redubbing existence as coexistence without justification, as Sartre, for instance, does (see Sartre 1971, p. 223). Furthermore, while Mitsein is introduced as an ontological qualification of the formal structural whole of Dasein, as such, we might raise the same worry as the one Levinas aims at Husserl in particular (Levinas 1998, p. 142): In a characteristic and remarkable text of his Krisis, Husserl goes to the point of claiming "to take lodging in the internal discourse, the discourse which goes toward all the others." "That which I am there stating scientifically," he writes, "is said from me to me, but at the same time, in a paradoxical fashion, I say it to all the others inasmuch as they are implicated transcendentally in me and the ones in the others." In the overcoming of skepticism and solipsism, the transcendental domestication of the world and others risks throwing alterity out with the bathwater. If the "other" is merely a transcendental other of consciousness (Husserl), or is restricted to one of the pillars of the house of Dasein (Heidegger), does the thread of solipsism not spook again, although from a different direction? The other "in" me is not an actual other-solipsism replaced by schizophrenia-like an uncanny twist from suspecting the girl I fancy to be an automaton (as in Hoffmann's Olympia), to suddenly doubt whether I, myself, could be an automaton. The Sandman enters Westworld.
Buber's move to wrest the subject from a self-enclosed isolation lies in a twofold dialogical relation (Buber 2004, p. 11): To man the world is twofold, in accordance with his twofold attitude. The attitude of man is twofold, in accordance with the twofold nature of the primary words which he speaks [ . . . ] The one primary word is the combination I-Thou, the other primary word is the combination I-It . . .
On the one hand, Buber's primal ontological relation is not transcendental if, by transcendental, we mean a formal structure cut off from experience. Rather, his account is "a phenomenological philosophy immersed in direct experience that avoids the transcendental turn to the ego" (Stawarska 2009, p. 119). On the other hand, Buber's account is not merely about a communicative discourse on an intersubjective or societal phenomenal plane, but is also about work on a transcendental level (see Eisenstadt 2002, p. 179). For Buber, the transcendental nucleus is the primal relation itself: "In the beginning is relation-as category of being, readiness, grasping form, mould for the soul; it is the a priori of relation, the inborn Thou" (Buber 2004, p. 28).
If the transcendental names that which precedes and constitutes the first-person perspective, the other can either be a transcendental other (i.e., just another "first-person perspective" like me), or a transcendent other, a "second-person perspective" that cannot be domesticated, yet transcends the sphere of the I. The difficult task for both Buber and Heidegger is to think through this relation between transcendental constitution and transcendent address.
Fundamental ontology, on Heidegger's account, is transcendental in the sense that it describes the constituent characteristics of the being of Dasein (die Seinscharaktere des Daseins) (Heidegger [1927(Heidegger [ ] 19961977a, pp. 17, 59). However, Buber's criticism of Heidegger aims at this formal notion of existence; or, what he calls, the "chemical purity" of the concept that does not address man in his actual manifold complexity (Buber 2002, p. 194). Since Heidegger's account is essentially about human existence in relation to its own being, the self becomes a closed system (ibid., pp. 198, 203). Here, Buber compares Heidegger's model to a game (ibid., p. 195f): We enter a strange room of the spirit, but we feel as if the ground we tread is the board on which a game is being played whose rules we learn as we advance, deep rules which we ponder, and must ponder, but which arose and which persist only through a decision having once been reached to play this intellectual game, and to play it in this very way.
If we use the analogy of chess, we can say that the existential-ontological level is the specific rules of the game and the existentiell-ontic level is the actual game that can be played out in innumerable ways. Although Heidegger does take into account a notion of beingwith-others, and characterizes the being of Dasein to be that of care or solicitude (Sorge), it remains formal in Buber's view: "In its essence solicitude does not come from mere co-existence with others, as Heidegger thinks, but from essential, direct, whole relations between man and man" (ibid., p. 201).
One might ask whether this critique of Heidegger misses the point completely, because it can be argued that fundamental ontology is nothing but a description and conceptualization of what is already going on, under the slogan "making it explicit", and not a formal construction that is rinsed to chemical purity and withdrawn from experience and factual life. The existential-existentiell division is, itself, only a methodological distinction. If we persist with the analogy of chess, we can say that Heidegger does not simply present a set of rules. Rather, like the nine-year-old chess prodigy, Beth Harmon (Anya Taylor-Joy), who deduces the rules of the game by watching the custodian Mr. Shaibel (Bill Camp) playing chess with himself in the basement of the orphanage in Scott Frank and Allan Scott's The Queens Gambit (Frank 2020), Heidegger simply describes, through phenomenological analysis, the game of existence already being played. In Heidegger's own words: " . . . we are always already involved in an understanding of being. From this grows the explicit question of the meaning of being and the tendency toward its concept" (Heidegger [1927(Heidegger [ ] 19961977a, p. 7).

Heidegger: (Re)writing the Rules of the Game
Despite this descriptive strategy, we might still object with Buber that the game Heidegger is playing is, essentially, one with a single player. As Buber states: "Life is not lived by my playing the enigmatic game on a board by myself, but by my being placed in the presence of a being with whom I have agreed on no rules for the game and with whom no rules can be agreed on" (Buber 2002, p. 197 (Heidegger 1956, p. 67). Furthermore: "the answer is not a reply (n'est pas une réponse), the answer is rather the co-respondence [Ent-sprechung] (la correspondance) which responds to the Being of being [die dem Sein des Seienden entspricht]" (ibid., p. 69). Heidegger does not, however, identify his notion of correspondance with adequatio in terms of a correspondence theory of truth, but rather with homologein: "The double language (cf. French and German) introduces here a difference in the same, or holds open the difference that allows agreement, homologein, correspondence, to occur. The difference is the difference of touching, passion, pathos, affection. Insofar as we are touched, philosophy is opened up to this realm" (Bernstein 2015, p. 617). In Heidegger's own words (Heidegger 1956, p. 73): Does not this correspondence constitute the fundamental trait of our nature? This is, indeed, the case. But if this is the case, then we can no longer say that we first have to attain this correspondence. And yet we are right in saying so. For, to be sure, although we do remain always and everywhere in correspondence to the Being of being, we, nevertheless, rarely pay attention to the appeal of Being.
The interesting point to note is that dialogue is not a speech-act performed on the basis of speech as a capacity, or a more original existential of Dasein on a transcendental level that first makes possible any dialogical encounter. Rather, the transcendental is, itself, at stake in the realm of dialogue between the appeal from Being out of the transcendental "always-already" and the pathic dis-position that enables us to hear and respond to the call (ibid., p. 83). 1 This idea of call and response works at the heart of Being itself. In On the Way to Language (1953), two years before the lecture held in Cerisy-La-Salle, Heidegger explicitly identified the art of hermeneutics, not with a fundamental pretheoretical always-already understanding and interpretation, but with something that addresses us in terms of a message. Heidegger (Heidegger 1971, p. 29;1985, p. 115): The expression "hermeneutic" derives from the Greek verb hermeneuein. That verb is related to the noun hermeneus, which is referable to the name of the god Hermes by a playful thinking that is more compelling than the rigor of science. Hermes is the divine messenger. He brings the message of destiny; hermeneuein is that exposition which brings tidings because it can listen to a message.
The original sense of hermeneutics is not that of interpretation, but rather the sending of a message (Botschaft). Heidegger explains that it was, in fact, this original notion of hermeneuein that opened the way to Being and Time (ibid., p. 30;1985, p. 116): What mattered then, and still does, is to bring out the Being of beings-though no longer in the manner of metaphysics, but such that Being itself will shine out, Being itself-that is to say: the presence of present beings, the two-fold [Zwiefalt] of the two in virtue of their simple oneness [Einfalt]. This is what makes its claim on man, calling him to its essential being.
Being is no longer conceived in terms of a formal structure, but rather as a buoyant field that bears a message. For Heidegger, this message is, ultimately, about the forgetfulness of Being (Seinsvergessenheit) in the technological age. The introduction of Hermes as the messenger of forgetting is related to Heidegger's concept of divinities (Götter) (that was already underway in Contributions (1936Contributions ( -1938) reaching a significant role in the Bremen-Freiburg lectures, Insight into that which is (1949), where they served as one of four constitutive regions of the fourfold (Geviert)-Heidegger's late concept of "world". The divinities hint of a lost manifold relation to Being compared to the age of technology, where Being is disclosed in one way and one way only-as standing-reserve (Bestand). Heidegger adopts Hölderlin's notion of the "hint" (der Wink) as "the language of the gods". Etymologically: "Winken has meant to let come, to intimate and stand in expectation, to near, and to call something here, bring it forth, and/or awaken it" (Mitchell 2015, p. 165f).
According to Jean-Luc Nancy, the wink not only borders the realm of sense and nonsense, but bends the two: "There is always excess, lack, or curvature of sense: winken is, in fact, first and foremost to curve or bow, to angle, vacillate, wobble, list [ . . . ] I speak of the clinamen, which creates a world of sense, while hinting at its truth in non-sense" (Nancy 2008, p. 169). This in-between sense and non-sense is opened by hints/winks: "a Wink departs from the established order of communication and signification by opening up a zone of allusion and suggestion, a free space for invitation, address, seduction or waywardness" (ibid., p. 170). With reference to a passage by Derrida, where he talks about the blink of the instant (Augenblick) as the alterity that conditions presence, Nancy goes on to identify this blink or wink as the very structure of différance-Derrida's signature idea. The in-between sense and non-sense, or the "(n)either-(n)or" per se of language in which any signpost may be deconstructed (différance), has the structure of winken (ibid., p. 173). For Nancy, this in-between is the passageway for that which signals a divine trait, the a of différance, and what Heidegger enigmatically names "the last god", which is the arrival of what only ever arrives in the mode of not yet arriving (i.e., the presence (arrival) of an absence (non-arrival) (Mitchell 2015, p. 171)). As Nancy states: "Whatever the unnameable nonmeaningful may be, the retreat of being into its différance, the bearer of the name, signals it. (And perhaps all bearers of a name signals it-perhaps God is present/absent at the heart of every name . . . )" (ibid., p. 178). For Heidegger, the wink would, rather, be the a of "la correspondance" that bears a message and a vocation for a different understanding of Being. Yet, what do the gods signify for Heidegger? Moreover, perhaps most importantly, what does the message say that Hermes delivers?
If we follow Vincent Vycinas, we can argue that Heidegger's notion of gods essentially builds on the model of the Greek deities, who should not be conceived in terms of supernatural beings, but as the very articulation of logos: "The Greek deity is not merely real. It is ultimately real because anything whatsoever can be real or not real only on the grounds or against the background of a deity" (Vycinas 1961, p. 187). Deities are, here, invoked in terms of different ontological backgrounds, or "worlds", that disclose Being in different ways. It is not the case, however, that each god dominates a specific domain of reality. Rather, everything is seen in a specific light when disclosed on the background of the world of Hermes, but the same phenomena appear differently when viewed on the background of Aphrodite, Hephaistos or Apollo, respectively: "Gods as worlds never merely dominate or support a section of reality; they dominate everything whatsoever. However, everything is shown and seen in a different light by a different god and therefore is different" (ibid., p. 188). The message Heidegger refers to is precisely a reminder of the manifold presencing of Being; the wide spectrum of its possible appearance that has been forgotten, overshadowed and lost, yet which, nevertheless, presents itself as absent through winken. These hints "constantly play out within a space in which different senses overlap, and in which the same term can carry multiple connotations" (Malpas 2016, p. 212).
Heidegger's move from fundamental ontology to a buoyant ontology is not a turn away from transcendental philosophy, but a modification of the transcendental. It is precisely the ontological difference between Being and being, from Being and Time, that now appears in terms of the twofold (i.e., the twofold between Being and being). Andrew J. Mitchell explains this buoyant structure as follows (Mitchell 2015, p. 185): The fold is a bend in an otherwise sheer field [ . . . ] The field is folded upon itself as though it were two, the whole time maintaining a space between the folded sheets or limbs. With Heidegger's emphasis upon a "two" fold, then, we are meant to hear the two "limbs" of the fold, the beings and being, as belonging together, to be sure, but nevertheless spaced apart from each other [ . . . ] In short, the twofold names the interface between being and beings, their separation from each other endemic to their belonging together.
The space in-between Being and beings is a palimpsest on which the two open ends of the fold constantly write and rewrite the rules of the game. This interface is dialogical in the sense that the message is both given and delivered. In other words, it is open on both ends by maintaining a relation to the donor (in order to be given) and the recipient (in order to be delivered) (ibid., p. 186). Furthermore: "The message extends between donor and recipient, it runs through them, dragging them out of themselves and exposing them each to the other. The Spruch of the Anspruch/Zuspruch names the hook by which the message catches us in contacting us and draws us out of ourselves to receive it" (ibid.). In this sense, man is a Janus-head figure, or placed in-between: "Then, man, as the message-bearer [Botengänger] of the two-fold's unconcealment [der Entbergung der Zwiefalt] would also be he who walks the boundary of the boundless." (Heidegger 1971, p. 41;1985, p. 129).
In Francisco J. Gonzalez' reading of the relationship between philosophy and poetry in Plato, he emphasizes the identification of both the poet and the rhapsode with the hermêneus which, as he argues, should not be translated by an "interpreter", but rather by a "mediator" (Gonzalez 2011, p. 94). In this sense: "Mere 'hermeneutics' is the mere transmission, without knowledge, of a message . . . " (ibid., p. 97). The art of philosophy, like poetry, is considered something "sent" or "god-given": "The contrast between poet and philosopher can only be one between two sorts of inspired madness or, in other words, between two ways of conveying a power and a message beyond either, between two forms of 'hermeneutics'" (ibid., p. 102). Philosophy and poetry begin from elsewhere, since they bear a message of a reality that transcends both of their domains (Boysen 2020, p. 89). Furthermore, in Eudemian Ethics 1248 a , Aristotle reminds us that reason itself originates in something other than itself, something superior; namely, the god who moves within (i.e., the concept ('to grasp' something) (Begrebet) presupposes an affection (to be moved/grasped by something other) (grebethed), (ibid., p. 118;Aristotle 2005, p. 39)). This is precisely what Heidegger, with reference to his Greek predecessors, named pathos, or Stimmung, as "astonishment" (θαυµάζειν)-the pathic disposition that originally opens the space of philosophy as dialogue (Heidegger 1956, p. 83ff): Only if we understand pathos as being attuned to [Nur wenn wir πάθoς als Stimmung (dis-position) verstehen], can we also characterize thaumazein, [das θαυµάζειν] astonishment, more exactly [ . . . ] We step back, as it were, from being, from the fact that it is as it is and not otherwise. And astonishment is not used up in this retreating from the Being of being [ . . . ] astonishment is disposition in which and for which the Being of being unfolds.
The dis-position names both an attuned space, in which dialogue can unfold as that which touches, affects and (at)tunes us, and a gesture of making room for something to unfold. The very logic of the message is logos as language and points to a buoyant ontology of dialogue (das Sprechen als Dialog); namely, as the relational interface of Being and being, where the donor and the recipient of the message are exposed to one another and where the ontological makeup of the transcendental-transcendent divide is constantly put into play, even if only through hints.

Buber: The Open System of Dialogue
If we return to Buber's critique of Heidegger's analytics of Dasein as a closed system and contrast his characterization of Heidegger's "single-player game", following strict rules with his own "two-player game" that is played in the presence of another with whom no rules can be agreed on, we can now modify this image. In the late Heidegger, the "transcendental board" and the a priori rules of the game constantly bend into a shared space, with beings affecting one another. If we look closely, Buber's game is, in fact, played in a similar way: "If a man does not represent the a priori of relation in his living with the world, if he does not work out and realise the inborn Thou on what meets it, then it strikes inwards" (Buber 2004, p. 56). In other words: "the primary word I-Thou can only be spoken with the whole being" (ibid., p. 17). The "whole being" refers to both the existentiell direct encounter, devoid of any foreknowledge or system of ideas, and to the transcendental a priori relation, not in the sense of a rigid set of persisting rules but, rather, in terms of an "open system of the human situation" (Buber 2002, p. 214): Connexion can mean only connexion with the integrality of his human situation. Neither the world of things, nor his fellow-man and community, nor the mystery which points beyond these, and also beyond himself, can be dismissed from a man's situation. Man can attain to existence only if his whole relation to his situation becomes existence, that is, if every kind of living relation becomes essential.
Buber does not reject the transcendental level and, instead, merges the transcendental, material and experiential dimensions of existence. The pretext for such a move is evident in Daniel (1913), in the section entitled "Reality" (Von der Wirklichkeit), where Buber emphasizes the capacity of a certain constitutive creativity and realizing force (Kraft der Realisierung) in, and through which, the "realizing man" (der Verwirklichende), as well as the objects that stand in his life-experience (Erlebnis), become reality (Wirklichkeit) (Buber 2018, p. 24;1919, p. 41). However, this does not mean that man, through his/her creative power, creates reality through and through. Buber does not affirm the correlation between thought and world, which would result in a closed system and, ultimately, grant reason absolute authority and exclude alterity for good (see Levinas 1998, pp. 139, 141). Rather, as Buber states (Buber 2018, p. 40;1919, p. 65): And it is not, indeed, my thought that beholds the abyss, it is my being [Wesen]: this thing made of stone and storm and flood and flame, this whole, weighing down, springing upward-this substance. There it stands, the elemental, and smiles at the beautiful bridges on which its child, thought, may dance.
From this quote, we learn that thought is an offspring of nature and not opposed to nature, and that thinking and experience are entangled in the transcendental material-the abyss and the elements. In I and Thou, this idea is expressed in the following way: "The It is the eternal chrysalis, the Thou the eternal butterfly-except that situations do not always follow one another in clear succession, but often there is a happening profoundly twofold [Zwiefalt], confusedly entangled" (Buber 2004, p. 21). Therefore, in the beginning is the primal relation of I-Thou, although it is entangled in the world of It, not merely as an ontic support or material underpinning, but as an open system, where stone, flood, flame, stars, creation and universe work as "conditions of the soul", and into which the Thou necessarily re-enters: "Every Thou in the world is by its nature fated to become a thing, or continually to re-enter into the condition of things" (ibid., p. 21).
While Daniel can be viewed as a transitional link between Buber's early "mysticism" and the philosophy of dialogue (Pattison and Kirkpatrick 2019), or as the very cognitive basis that underlies I and Thou (Koren 2002), it also lays the groundwork for a transcendental-material entanglement in, and through which, realization (Daniel), or the primal relation (I and Thou), unfolds. The openness of this system consists of at least three aspects:

If the a Priori of the Primal Situation Must Constantly Be Represented in Actual Life, "Dialogue" Must Take Place across the Transcendental-Transcendent Divide of Existence
In The Word that is Spoken (1960), Buber distinguishes between three modes-of-being of language (Seinsweisen der Sprache) in the life each of us live (i.e., "present continuance" (präsenter Bestand), "potential possession" (potentialer Besitz) and "actual occurrence" (aktuelles Begebnis)). The first mode signifies "the totality of that which can be spoken in a particular realm of language in a particular segment of time regarded from the point of view of the person who is able to say what is to be said" (Buber 1965, p. 110). The second mode names "the totality of what has ever been uttered in a certain realm of language" (ibid.). The first two modes "serve" (dienen) the third mode of utterance-the word that is spoken (ibid., p. 111). In this sense, what is uttered is supported by these modes as the background upon which the spoken word occurs. However (ibid., p. 112): If we could take an inventory [Inventarium] of all the physical and psychic phenomena to be found within a dialogical event [eines dialogischen Vorgangs], there would still remain outside something sui generis that could not be included-and that is just what does not allow itself to be understood as the sum of the speech of two or more speakers, together with all the accidental circumstances. This something sui generis is their dialogue [Gespräch].
The word that is spoken is located in the oscillating sphere between persons. The first type of openness consists of the irreducibility of this "in-between" (das Zwischen) of dialogue. The ontological-transcendental condition is "speech" considered as the first two modes of being. In I and Thou, it is stated that: "in actuality speech does not abide in man, but man takes his stand in speech and talks from there" (Buber 2004, p. 36). However, this notion of topological envelopment suggests not a background, but an open space that supports the lungs and nourishes the spirit. Man takes his stand in speech and talks from there, "so with every word and every spirit. Spirit is not in the I, but between I and Thou. It is not like the blood that circulates in you, but like the air in which you breathe" (ibid.). Dialogue transcends the rules of the game, since everything is in play in the word that is spoken, and this in-between remains an irreducible sphere. It is the word itself, in its ambiguity (Mehrdeutigkeit) that constitutes living language (Buber 1965, p. 114).

While the In-Between of I and Thou Can Never Be Reduced to the Sum Total of Components of the Dialogical Situation, in Daniel, Buber Explicitly Announces a Certain Realist Position, If Only for a Brief Moment
When the interlocutor Ulrich asks Daniel whether things are only real for the realizing man, Daniel responds: "It would be very much preferable if we did not assert that the things are real 'for him.' Is the fire there for the iron or the iron for the fire or both only for the smith? No matter, the steel really comes forth and works" (Buber 2018, p. 24). Things are, hence, not created by man in and through his realizing power (whether considered ontologically or epistemologically), but, instead, "comes forth and works" (wirkt), not only as an object over-and-against man, but in terms of an object (iron) for another object (fire). Buber does not reduce reality to the human-world correlation, but allows a mindindependent reality that he views not merely as an abstract "world of things", but in terms of concrete relations between entities such as fire and iron (Buber 2018, p. 25;1919, p. 43): Reality for whom? For all, because out if it a seed of realizing falls in all? For a self that experiences us and receives from us nothing other than our reality? For no one? It does not matter: it is, and is not less if it is beheld by no eyes [Sie ist, und ist nicht geringer, wenn Sie vor keinem Auge ist].
The abysmal experience reported by Reinold, the interlocutor of Chapter 3, "On Meaning", is, in fact, a moment of vision into this model of reality: "The abyss was between piece and piece of the world, between thing and thing, between image and being, between the world and me" (Buber 2018, p. 38;1919, p. 62). This multiple abysmal condition of things suggests a rather open notion of the real, where relata and relations cannot be reduced to one another, but co-work. Although Buber is most interested in the human-world relation, this relation does not exhaust reality per se, but simply names "the essential form of existence" (die wesenhafte Gestalt des Daseins), not the only form" (Buber 2018, p. 24;1919, p. 42).

The Third Kind of Openness Refers to What Buber Calls the "Eternal Thou"
"The extended lines of relations meet in the eternal Thou. Every particular Thou is a glimpse through to the eternal Thou; by means of every particular Thou the primary word addresses the eternal Thou" (Buber 2004, p. 61). According to Buber, the eternal thou is precisely what makes the "system" open, in contrast to Heidegger's model. While Heidegger draws heavily on Kierkegaard's thought, he also secularizes what Kierkegaard named "the Single one". Buber states that: "Heidegger's self is a closed system [ . . . ] Kierkegaard's Single One is an open system" (Buber 2002, p. 203). However, while this category of the human is essentially open (i.e., open to God or the Absolute), Heidegger's secularized version excludes any such notion of an Absolute other or eternal thou: "Heidegger speaks of man becoming 'opened' to his self; but this self itself to which he becomes opened is by nature closedness and reserve" (ibid.). Buber's objections toward Heidegger's model add up to the following two points: (1) the notion of self or Dasein is too formal and (2) it does not participate in any essential relation to the other, whether considered as the other human being or the absolute other.
Similarly to Heidegger, however, Buber identifies dialogue as an original event: "Language never existed before address [Ansprache]; it could become monologue only after dialogue broke off or broke down" (Buber 1965, p. 115). While Heidegger speaks about the address of the absent gods as the hinting messengers within a mythological framework, Buber refers to God's address in a theological framework. In both cases, however, the event opens up a multiple dimensionality; the aura (Aura) of Mehrdeutigkeit for Buber and the hint of a lost relation to Being in its plural disclose-ability for Heidegger. Unlike Heidegger, Buber most strongly emphasizes not only the transcendental structure or the original happening, but points to the addressee, the speaker and "his factual existence in all its hidden structure" (Buber 1965, p. 120). While Heidegger identifies this opening as aletheia, "unconcealment", by reference to the Greeks as the qualification of primordial "truth", Buber advocates a different model of truth as "faithfulness" (Treu) 2 , which "opens itself to one just in one's existence as a person. This concrete person, in the life-space allotted to him, answers with his faithfulness for the word that is spoken by him" (ibid.). In the words of Paul Mendes-Flohr: "To Buber's mind Heidegger's principal focus on the ontological structure of language neglects the intersubjective dimension of the spoken word" (Mendes-Flohr 2014, p. 19). In short, while Heidegger emphasizes the Being of beings, Buber emphasizes the Being of beings.
The greatest difference between Heidegger's relationality of the ontological difference and Buber's primal relation is that, whereas Heidegger never leaves the always-alreadyness of transcendental philosophy, not even in the fourfold, the relation between I and Thou does not make up an equiprimordial trichotomic unity for Buber. Rather, the in-between is primary, in the sense that I and Thou first come to be in the meeting. Theunissen states that: "Instead of the I and Thou, as already finished beings, bringing the meeting into being, they must, according to the dialogical approach, themselves first spring out of the occurrence of the meeting" (Theunissen 1984, p. 280;1977, p. 269). If the relation itself is primary, who, then, occurs in the meeting, if there is no one (relata) to meet? Theunissen explains this aporia by distinguishing between the native and the encountered Thou in Buber: "The native Thou is an a priori structure of my being constitution and, as such, the condition of the meeting [ . . . ] In contrast, the encountered Thou is simply the a posteriori fulfillment of the a priori . . . " (Theunissen 1984, p. 293;1977, p. 280). What I have called buoyant ontologies refers to the pliancy between the transcendental and the existentiell-ontic level in both Buber and Heidegger. Let us turn to the buoyancy of the transcendental itself.

The Transcendental "Chess Game" Revisited
Let us take a step back and reconsider the role of the transcendental. Let alone the medieval usage, the modern notion of the transcendental starts with Immanuel Kant. For Kant, the transcendental does not signify any relation of our cognition to things, but names the very faculty of cognition (Kant 2002, p. 88, Prol. 4: 294). In Critique of Pure Reason (1781), Kant offers the following definition: "I call all cognition transcendental that is occupied not so much with objects but rather with our a priori concepts of objects in general. A system of such concepts would be called transcendental philosophy" (Kant 1998, p. 133, KrV. A12). Furthermore, Kant distinguishes between the transcendental and the transcendent in the following way (Kant 2002, p. 161n, Prol. 4: 374): the word: transcendental [ . . . ] does not signify something that surpasses all experience, but something that indeed precedes experience (a priori), but that, all the same, is destined to nothing more than solely to make cognition from experience possible. If these concepts cross beyond experience, their use is then called transcendent . . .
In short, for Kant, the transcendental names the "conditions of the possibility of experience", while the transcendent signifies that which is beyond possible experience (Serck-Hanssen 2003, p. 7). More broadly, we can say that Kant introduces a framework for thinking about the question of being, or the question of "ground", in a new way (Malpas 2003, p. 76). However, for Heidegger, the transcendental and the transcendent aim at the same; namely, "Being". Being is not, itself, a being, but that which determines beings as beings (Heidegger [1927(Heidegger [ ] 19961977a, p. 10). Hence, "The question of being thus aims at an a priori condition of the possibility [ . . . ] of the ontologies which precede the ontic sciences and found them" (Heidegger [1927(Heidegger [ ] 19961977a, p. 15). In this sense, the investigation aims at a transcendental inquiry. At the same time, however, Being itself is identified with transcendence per se: "Being and its structure transcend every being and every possible existent determination of a being. Being is the transcendens pure and simple" (Heidegger [1927(Heidegger [ ] 19961977a, p. 51). "Transcendence", here, is not conceived in terms of God or substance, but as the potentiality-to-be of Dasein's ecstatic temporality (see Grøn 2007, p. 28).
If we count "experience" to be in the realm of what Heidegger coined the ontic and/or existentiell, along with material objects, there is (at least in the early framework of Being and Time) a clear division between Being and beings-the ontological difference. However, in the late Heidegger, as we have seen, the point of departure is no longer the supposed relata of the ontological difference, but rather the interface of Being and beings, or simply the relationality in-between (Mitchell 2015, p. 320). Already in On the Origin of the Work of Art (1935Art ( -1936, Heidegger emphasized what he called the strife of world and earth. Although he clearly states that earth is not to be confused with "matter", it is, nevertheless, opened up through objects, including the peasant shoes as illustrated on a painting by Van Gogh: "From out of the dark opening of the well-worn insides of the shoes the toil of the worker's tread stares forth [ . . . ] On the leather lies the dampness and richness of the soil" (Heidegger 2002, p. 14;1977b, p. 19). Although the earth itself does not refer to materiality as such, the shoes (a material object) are, nevertheless, said to "vibrate with the silent call of the earth" (ibid.). The earth is moved into the world through the shoes, as portrayed in the artwork. Soil and stone, and mud and field belong to the realm of earth and all these "material conditions" co-appear in, and through, the world, as that upon which the world is grounded, while the earth itself withdraws. The world, on the other hand, names the appearance of what is opened-the horizon of meaning: "World is grounded on earth, and earth rises up through world" (Heidegger 2002, p. 26;1977b, p. 35).
In contemporary philosophy, this "buoyancy" of the transcendental and the material has gained new attention. In Eugene Thacker's Horror of Philosophy (2011), the earth refers to natural disasters, climate change, the specter of extinction, ozone and the carbon footprint. In other words, the earth is when the "world" bites back and "resists, or ignores our attempts to mold it into the world-for-us" (Thacker 2011, p. 4). Thacker names the fissures, lapses or lacunae of the earth and world as the planet or the world-without-us: "Anything that reveals itself does not reveal itself in total. This remainder, perhaps, is the 'Planet.'" (ibid., p. 7). In his Sydney Lectures in philosophy and Society, David Wood takes up Plato's example of the Sun as a key example of an object that blurs the distinction of the ontological difference: "The Sun is the ultimate hybrid being-material yet transcendental" (Wood 2018, p. 22). Furthermore, anthropogenic climate change has made clear that philosophy cannot approach this new situation through a rigid distinction between the transcendental and material. As Wood states: "If philosophy itself relies on maintaining something like the ontological difference, or a gap between material and transcendental, arguably the event of the Anthropocene is that it blows this rigid distinction out of the water" (ibid.).
In Catherine Malabou's latest work, Before Tomorrow (2016), she offers a new interpretation of Kant's notion of the transcendental. She takes her point of departure in a phrase from §27 of the second edition of the first Critique, where Kant talks about the "System of the epigenesis of pure reason" (Malabou 2016, p. 16). "Epigenesis" is a concept casted from biology to help explain the very origin of the correlation, or "agreement", (Übereinstimmung) that connects the transcendental categories to the objects of experience a priori (ibid.). This agreement concerns the "original acquisition" (acquisitio originaria) of the categories that can be neither "innate", nor come from experience or an empirical source. Instead, Kant aims for a model that explains the pure production of the categories, or a system of the epigenesis of pure reason (ibid.). In contrast to genesis, which measures the journey of evolution from an origin (i.e., from past to present), epigenesis takes place in "the moving contact point between origin and the present state of affairs" (ibid., p. 157). Malabou uses the example of an earthquake in order to illustrate this activity (ibid.): the epicenter of an earthquake is the projection point of its focus or hypocenter. The epicenter marks the exact point of the eruption, the place where the surface of the earth opens, cracks, bursts. Between ground and underground, the epicenter is thus in some ways the contact point of the earth with itself [ . . . ] In this instance, the notion of an in-between base and surface is thus a decisive factor. The logic of this in-between is also at work in epigenesis. In the Critique of Pure Reason, Kant situates transcendental epigenesis as the development that occurs upon contact between categories and experience.
In this sense, the in-between is the very meeting point, not only between the "old" and the "new", but the very "space where they reciprocally interfere and transform one another" (ibid., p. 158). Within the system of reason, epigenesis names a transcendental transformative force that secures both stability and mobility through a logic of prospectiveretrospective activity: "No gestation without retroaction, such is the law of epigenesis (ibid., pp. 156, 175).
In order to define transcendental epigenesis, Malabou points to Ricoeur's notion of hermeneutic epigenesis that helps us question meaning in a specific way. The task is, once again, to understand whether meaning lies in genesis (a return to the old) or in epigenesis (a rectification of the old by the new). In Ricoeur's terminology, hermeneutic epigenesis names the "intersection of the archaic and the teleological" and, hence: "Meaning therefore lies in the way in which a principle becomes its result. Teleology is a prospecting tension towards the future which rectifies after the fact the primitive or 'archaic' dispositions that made it possible" (ibid., p. 158). Although transcendental and hermeneutic epigenesis are different, they follow the same logic of prospection and retroaction in the "in-between". It is about the very modification of the production of a preformed categorial engendering (transcendental) by experience after the fact (ibid., p. 159). In this sense, the transcendental is not merely an invariant set of rules by which the game of experience is played. Rather, the transcendental is, itself, modified and transformed, and the categories are, themselves, changeable (ibid., p. 172f). As Malabou states: "The transcendental in Kant is a constant dialogue between two dimensions: our inherited structures of thinking and the possibility of critical discourse on these structures" (Malabou 2017, p. 248). Through the lenses of the third Critique, Malabou even argues that the transcendental is somehow evolving because Kant analyzes the transcendental as a living being 3 (ibid., p. 244).
If we return to Buber's game analogy and use the example of chess once again, we do not simply face a model where the transcendental represents the rules, and experience represents the 10 43 possible outcomes of a game played by these rules (see Shannon 1950). Rather, if we take the history of chess into account, the rules of the game changes too. The queen, for instance, started out as a "male counsellor" (mantri) with limited power moving one square diagonally, before extending into a two-square leap, adding the leap of the knight, and, for a short period of time, the right to play the role of any piece on the board, to finally being able to move as the rook and the bishop-the present move (Davidson 1949, p. 28ff). The change of sex happened due to homophony of the words fierge (from fers, "counsellor") and vierge ("maiden" or "virgin"), implying "The Holy Virgin, Our Lady, Queen of the Angels", a designation that persisted through much of central Europe (as donna or dama) in late medieval times, where chess was being thought of as a royal court rather than a replica of battle (ibid., p. 29f).
Furthermore, the rook was originally either a ship or a chariot, not a castle. The philological arguments for the ship theory orbits around the word rook which is close to roka-the Sanskrit word for "ship". As chess historian Duncan Forbes has argued, the vast alluvial plains of the Panjab, and those bordering on the Ganges, are flooded with water arising from the melting of mountain snow for almost a third of the year, which indicates that boats must have formed an important item in the materiel of any army of such countries (ibid., p. 42). Similar topo-cultural arguments have been made in favor of the chariot theory. H. J. Murray has argued that it is very unlikely that ships ever worked as components of an Indian army and, hence, the corner piece of the original Sanskrit chess, chaturanga, was not a ship but a ratha-Sanskrit for "chariot". The word ratha was likely translated into the Persian rukh, "chariot", since all of the other Sanskrit chess names were translated into Persian as well (ibid., p. 43). The shape of the rook as a castle might stem from the Italian word rocca, meaning "fortress", or simply because mobile towers were popular war machines throughout the middle ages (ibid., p. 46). However, not all pieces changed so dramatically. The move of the knight has not varied for 13 centuries (i.e., the asva, "horse", moved in the Sanskrit game exactly as the modern knight (ibid., p. 51)). Therefore, chess was not merely played by the rules, but the rules changed due to the play, particularly between 1200 and 1600-a four-hundred-year period characterized by "experimental variations designed to increase the speed of the game and offer greater premiums to alertness and long-range strategy" (ibid., p. 13).
What I have called "buoyant ontologies of dialogue" in Buber and Heidegger follow this kind of game strategy. Of course, the rules of chess and the categories of the transcendental cannot be compared one to one because, in the case of the former, we never leave the empirical realm, while in the case of the latter, we discuss that which precedes and organizes our access to the empirical realm. Nevertheless, the rules of the game (transcendental) and the ongoing play (experience and factual life) are negotiated in a prospective-retrospective dialogue, always beginning from elsewhere, again and again with an address.

Conclusions
Both Buber and Heidegger operate within the framework of Kant's transcendental legacy. However, their different approaches toward the question of human existence take place not as a transcendental inquiry alone, but rather in the relation between a transcendental a priori and a transcendent address. While Heidegger wrests free of potential solipsism by pointing to the transcendental structure of the shared horizon of meaning that first makes possible any doubt about externality, it is questionable whether this move is, itself, a domestication and exclusion of the factual encounter with others, as Buber argues. In Heidegger's later thought, however, the interface between a transcendental structure and a transcendent address is brought to the fore as the twofold (Zwiefalt). In Buber's relational ontology, the transcendental, material and existentiell dimensions are merged into a primal relation of I and thou-a dynamic in-between (Zwischen) already underway in his early work. For both Buber and Heidegger, this buoyant field where the transcendental and the transcendent meet and transform one another is called dialogue. In contemporary continental philosophy, the idea of the transcendental as a flexible and transformable structure, rather than a fixed set of rules, has gained attention. The thread of mass extinction in the wake of anthropogenic climate change not only calls for buoyant thinking, but exposes the buoyancy of Being and beings. Hot air is already a conversation starter. It is the air we breathe. Dialogue has already, inevitably, emerged in the human condition of the 21st century and will persist for thousands of years to come. What do we respond when the message of the address sounds terrifying, like icebergs melting? "Queen to D8. Check!" A countermove will not do. Even if we avoid a checkmate, we will eventually lose the tournament because this is a game we play against ourselves. We are facing speciocides, not a terracide. We have to change the rules of the game, and dialogue has the power to do that.
Funding: This research received no external funding.

Conflicts of Interest:
The author declares no conflict of interest.

1
As always, Heidegger shares a lot with Kierkegaard here. The model of call, address and response is most significant in Heidegger's later writings, while for Kierkegaard, it is at the center of his philosophy. For a thorough analysis of the address of existence in Kierkegaard, see (Hansen 2021).