Heidegger’s Sein und Zeit is famous for pushing the question of being (“der Sinn des Seins überhaupt”) to the forefront of philosophical inquiry – and for offering as a preliminary horizon for answering this question an investigation into the threefold structure of time (past, present, future). For Heidegger, every explicit or implicit interpretation of being (Seinsverständnis) held by a human being (Dasein) can and must be explained on the basis of a deeper systematic account of the temporal structure of being. To render the thesis of being as time plausible, Heidegger spends most of the book reinterpreting a host of typical, but also atypical, subjects of ontological inquiry, like things, signs, world, space, sociality, normativity, emotion, understanding, language, truth, silence, fear, conscience, and death. This paper asks what role logical modality (possibility, actuality, necessity) plays in his account of temporality (Zeitlichkeit), and argues that the link between the two provides an important insight in the systematic nature of his philosophical operation.
Heidegger’s reiterates the preliminary result of his investigation into the question of being time and again in a number of vocabularies, and, always as a threefold temporal structure. After having established Heidegger’s own presentation of his threefold temporal structure at the base of Dasein, I will show how each of the tree temporal ecstasies relates to either possibility, actuality or necessity, a relation Heidegger does not make explicit but, as it turns out, once foregrounded, enables a modal interpretation of his ontology.
1. The threefold structure of Dasein’s fundamental temporality
Here is how Heidegger characterizes the co-constitutive character of the three temporalities:
“Zukunft, Gewesenheit, Gegenwart zeigen die phänomenalen Charaktere des »Auf-sich-zu«, des »Zurück auf«, des »Begegnenlassens von«. Die Phänomene des zu . . ., auf . . ., bei . . ., offenbaren die Zeitlichkeit als das ἐκστατικόν schlechthin. Zeitlichkeit ist das ursprüngliche »Außer-sich« an und für sich selbst. Wir nennen daher die charakterisierten Phänomene Zukunft, Gewesenheit, Gegenwart die Ekstasen der Zeitlichkeit. Sie ist nicht vordem ein Seiendes, das erst aus sich heraustritt, sondern ihr Wesen ist Zeitigung in der Einheit der Ekstasen.“
The three temporalities have in common that they are each a fundamental way for Dasein to be outside of itself, in the world. None of the three has a prior status. Similarly in his definition of care (Sorge):
“Als Grundverfassung des Daseins wurde die Sorge sichtbar gemacht. Die ontologische Bedeutung dieses Ausdrucks drückte sich in der »Definition« aus: Sich-vorweg-schon-sein-in (der Welt) als Sein-bei (innerweltlich) begegnendem Seienden.“
Again, we find a strict insistence on the co-constitutive status of the three ecstasies. Dasein is constituted by each of the three ecstasies not merely because the world appears to him/her fundamentally temporalized, but especially so because his/her finite being is at stake in each of them. For Heidegger, the catch is that what is ‘at stake’ is tripartite. To ‘be’ is to inhabit this threefold pull away from being what would be a self-contained subject. This ternary structure is neither a (secondary) subdivision of a higher concept into its constitutive parts, nor a result of a dialectical operation, in which a third term sublates two conflicting terms. To the contrary, the three terms future, past, and present are equally original (gleichursprünglich) as Heidegger emphasizes time and again, each of them relies on the other two to derive its full meaning, and together they serve to explain the concept of time, which turns out as nothing less than this temporalization in three directions.
2. Temporality and modality
Now that the co-constitutive character of the three temporalities has been indicated, I will proceed by showing how modal terms occur in Heidegger’s explanation of each of the temporalities. This connection should interest us, because modality is usually considered in the domains of logic and epistemology; whereas, I claim, Heidegger transports it to the domain of the ontology of Dasein.
2.1 Futurity as possibility
The way in which future becomes synonymous with possibility is perhaps most obvious. For Heidegger, future is nothing less than the possibility-character of that which is coming towards Dasein: “’Zukunft’ meint hier nicht ein Jetzt, das, noch nicht ‘wirklich‘ geworden, einmal erst sein wird, sondern die Kunft, in der das Dasein in seinem eigensten Seinkönnen auf sich zukommt.“ Seinkönnen, potentiality-for-being: Dasein in the mode of futurity approaches fundamentally as a possibility. And a possibility which is not merely what is not yet actual, he explicitly denies the explanation of future/possibility as actuality to come. Inasmuch as we project ourselves towards a future (Entwurf), we understand the possibility-character of our futurity, without reducing our futurity to a something which can be planned in a clear-cut way: “Das Verstehen ist, als Entwerfen, die Seinsart des Daseins, in der es seine Möglichkeiten als Möglichkeiten ist.”
But Heidegger clarifies that ‘possibility’ is here not to be understood either as a ‘logical’ possibility (either/or) or as a sign of some kind of contingency. “Das Möglichsein, das je das Dasein existenzial ist, unterscheidet sich ebensosehr von der leeren, logischen Möglichkeit wie von der Kontingenz eines Vorhandenen, sofern mit diesem das und jenes ‚passieren‘ kann.“ Possibility, as existential, is neither: what is possible is conditioned by the past, so never ‘random’ (anything could happen); and for the same reason it cannot be a ‘formal possibility,’ derived from the symmetry of possibility (if this is possible, then the opposite is too). Dasein’s possibility, as elaboration of futurity, is always already a corrective to a situation.
To understand how existential possibility is ‘framed,’ we move on to discuss past (necessity) and present (actuality).
2.2 Having been (Gewesenheit) as necessity
Now, as I claimed earlier, the past becomes linked to the modality of necessity. From a common sense perspective there is some obviousness to this too, because what has passed may no longer be actual but must be regarded as causally necessary for what happened after, all the way up to now. But if Heidegger indeed requires a structural affinity between having-been (past) and necessity, it will be in a way rather sharply distinguished from this ‘common sense view,’ because it is yet another incarnation of the vulgar concept of time, positing the past as a now (necessarily) before the present-now, effectively using the present as a false center of ontology. Rather, the past has to be thought as co-constitutive of present and future. How then is such a connection between past and necessity established?
For Heidegger, Dasein’s possibility must somehow be pre-structured by a necessary past in a way which does not foreclose its openness (geworfene Möglichkeit). This pre-structuration of Dasein’s possibility comes from the world, and is unique to each Dasein. Heidegger has a term for this structuring, but not wholly determining, direction: “thrownness” (Geworfenheit), which denotes the specificity of each Dasein in its ‘there’ (Da):
“Diesen in seinem Woher und Wohin verhüllten, aber an ihm selbst um so unverhüllter erschlossenen Seinscharakter des Daseins, dieses ‘Das es ist‘ nennen wir die Geworfenheit dieses Seienden in sein Da, so zwar, daß es als In-der-Welt-sein das Da ist. Der Ausdruck Geworfenheit soll die Faktizität der Überantwortung andeuten.“
Dasein as such is thrown from some undisclosed place towards another undisclosed place. And yet, it can, in a relative way, restructure the throw towards other directions. Heidegger calls this ‘projection’ (Entwurf) and this possibility belongs to futurity. But thrownness is from somewhere. It is this undisclosed whence of the throw which is what connects Dasein to the past. Indeed, the character of having been (Gewesenheit) is elaborated in reference to the throw: “Übernahme der Geworfenheit aber bedeutet, das Dasein in dem, wie es je schon war, eigentlich sein.” Consequently, Heidegger thinks Dasein’s authentic relation to the past as a repetition (Wiederholung) of the past inasmuch as it contains specific possibilities, with which Dasein has to come to terms, his/her inheritance (Erbe). Thus, the necessary background of possibility is described as that which both enables and delimits possibility simultaneously.
Heidegger also uses the term “facticity” to indicate the stringent character of Dasein’s relation to the past. It is noteworthy that he thereby articulates a type of necessity which is not framed in strictly epistemological terms (apodicticity), logical terms (entailment), or historical/eschatological terms (unavoidability). Instead, it explains how the temporality of Dasein holds the radical specificity of being one person, and not another: in other words, the necessity of having come from somewhere specific, of being a specific becoming. As such, possibility and necessity keep each other in check simultaneously. Possibility is pre-structured yet restructurable; necessity is determining yet inheritable. We also find this insight when Heidegger discusses freedom: “Freiheit ist nicht die Ungebundenheit des Tun- und Nichttunkönnens. Freiheit ist aber auch nicht erst die Bereitschaft für ein Gefordertes und Notwendiges.“ Necessity must thus exercise a pull on Dasein without being wholly deterministic.
2.3 Present as actuality
The third prong of Heidegger’s threefold temporal schema is the present (Gegenwart). Here I want to show how he links the present with actuality whilst simultaneously critiquing a certain notion of actuality/reality which does not recognize its co-constitution with the other modalities.
Earlier we established that Heidegger regards the present to have the phenomenal character of ‘letting-oneself-be-encountered-by’ (Begegnenlassen von). “Begegnenlassen gründet in einer Gegenwart. Sie gibt überhaupt den ekstatischen Horizont, innerhalb dessen Seiendes leibhaftig anwesend sein kann.“ But this bodily presence of beings needs to be correctly situated in ontology. For Heidegger, the main mistake that pretty much all of Western metaphysics has made is that it used that which is present in the now as the starting point for all ontological inquiry. Ontology, the question of being, was univocally and exclusively taken up as an investigation into the deeper nature of bodily presences in the now (idea, ousia, substance, etc.), thus neglecting questions of time.
But, once the question regarding the meaning of being is correctly posed, it becomes clear that a prior investigation into the ontology of (human) Dasein is the only correct way into ontology in general, because it is Dasein and Dasein only that asks the question regarding the meaning of being. If we accept Heidegger’s argument that ontology has to start with an investigation into the ontological structure of Dasein and his result that this structure consists of a co-constitutive set of three temporal modes, we can understand his notion of the present (Gegenwart). The presence of bodily beings in the now can no longer be the privileged site or model for ontology; instead, it has to be positioned as one of three directions in which Dasein is outside-of-itself that always implies the other two.
He accordingly explains the present as the mode in which things appear to us, not as objects of a disembodied scientific inquiry, but first and foremost as pragmatic objects: equipment, paraphernalia, gear, etc. (Zeug), which stand in larger contexts (Zeugzusammenhänge). Because Dasein’s primary mode of engaging beings/things in the present (Wirklichkeit) is broadly pragmatic, it cannot be disconnected from the other temporalities/modalities, for, a pragmatic context is always pre-structured (past/facticity) and always towards some other state (future/possibility). Indeed, only when the present is rid of its pragmatic character can it emerge as the privileged site of ontological inquiry in which things would be fully present and from where their being can be determined. Once the way in which bodily beings appear to us in the present is conceived of pragmatically, we consequentially have to conceive of the present as co-constitutive with past and future, because the pragmatic thing can only be thought consistently in relation to Dasein, which is temporal.
Accordingly, the modal term which Heidegger embraces is not “reality,” but “actuality” (Wirklichkeit). It denotes the beings that Dasein encounters in the now, always originally from the pragmatic point of view, in actu.
I have shown how each from each of the temporal terms of Heidegger’s Being and Time seems to correspond to one modal term, which also acquires a precise meaning from its context.
3. Conclusion: being and modality?
The meaning of modal terms in Sein und Zeit, although unqualified by Heidegger himself, should not be regarded a philosopher’s habit or even something for which we necessarily need to seek explanations outside of his text (for example, in Kant’s table of judgments or in Aristotle’s Posterior Analytics). Rather, the use of the three modal terms possibility, actuality, and necessity emerges from the text operatively in conjunction with the three co-constitutive temporalities which Heidegger claims to be at the basis of the fundamental ontology of Dasein. At the very least, an attention to how modal terms operate greatly aids our understanding of Heidegger’s concept of Dasein. In fact, it has become clear that the specific temporal structure of Dasein cannot be understood without the (altered) modal terms which serve to explain it. One should dwell on the relationship between ontology, time and modality, and on the question whether an ontological grounding as attributed to Heidegger, is a tenable position.
Two strong points of Heidegger’s ontology with regards to modality are:
- Just like the three temporalities, the three modalities are explained as co-constitutive of Dasein. Neither of the terms is explained by derivation from the other, nor does the emergence of the region of, for example, the possible depend on, for example, the necessary.
- The modal terms emerge from an interpretation of everydayness, aiming towards an ontology of Dasein. As such, Heidegger neither localizes the necessary in the theological, nor is his theory grounded in the analysis of modal sentences (modal logic). Rather, he attempts to situate modality in the oftentimes non-discursive modes of being towards, from, and at of Dasein.
This raises questions about the relationship between the here outlined grounding of modality in the ontology of Dasein and the way modality is used in logic and metaphysics, where it occurs in the context of statements of truth. Can an understanding of the latter usage of modality be derived and alternatively explicated from Heidegger’s fundamental ontology? Does Heidegger’s critique of the vulgar concept of time imply a critique of a vulgar concept of modality? Are temporality and modality ultimately grounded in the same ontological structure?
Heidegger, Martin. Sein und Zeit. Tübingen: Max Niemeyer Verlag, 2006.
Heidegger, Martin. Vom Wesen der Wahrheit. Frankfurt am Main: Vittorio Klosterman, 1943.
 Martin Heidegger, Sein und Zeit (Tübingen: Max Niemeyer Verlag, 2006), 328-329.
 Ibid., 249.
 Ibid., 325.
 Ibid., 145.
 Ibid., 143.
 Ibid., 135.
 Ibid., 325.
 Martin Heidegger, Vom Wesen der Wahrheit (Frankfurt am Main: Vittorio Klosterman, 1943), 15.
 Martin Heidegger, Sein und Zeit, 346.