Martin Heidegger: The Metaphysical Foundations of Logic

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Book review by Renxiang Liu, originally written in Dec 2020.

The book contains Heidegger’s Summer 1928 lectures delivered at Marburg University (GA26). Like the Winter 1925/26 lectures (GA21, Logic: The Question of Truth), they start with traditional logic and end with a suggestion that Temporality [Temporalität], and thereby Dasein, are at the heart of apparently ‘technical’ problems of logic.

What distinguish the 1928 treatment from the 1925/26 version are the following. First, instead of beginning with Husserl and finishing with a Kant-interpretation, Heidegger dedicates half of the lectures to Leibniz’s logic and its “metaphysical foundations”. Second, instead of focusing on truth and falsehood, Heidegger highlights transcendence—and, accordingly, freedom and ground [Grund, usually translated as “reason” as in the Principle of Sufficient Reason]. This means subjectivity plays a more important role here. Third, fundamental ontology, i.e., the investigation into the meaning of Being in general [der Sinn von Sein überhaupt], begins to converge with the analytic of Dasein, leaving room for a further step of “metontology”, i.e., the study of “beings as a whole” [das Seiende im Ganzen] or “a possible totality of beings.” (157) This step is a “turn” [Kehre] at which “ontology itself expressly runs back into the metaphysical ontic in which it implicitly always remains,” thereby completing metaphysics (as incorporating both fundamental ontology and the newly articulated metontology). (158) The metaphysics of Heidegger’s middle-period, observable in GA3 (Kant and the Problem of Metaphysics, 1929), GA29/30 (The Fundamental Concepts of Metaphysics: World, Finitude, Solitude, Winter 1929/30 lectures), and GA40 (Introduction to Metaphysics, Summer 1935 lectures), emerged here in 1928.

The lectures begin with a dissatisfaction with traditional logic: while the operation with so-called logical rules is banal and almost automatic, Heidegger insists that philosophy must “make the obvious incomprehensible and the unquestioned something questionable”; it bears the task of “shocking common sense out of its presumptive self-glorification.” (6) When it comes to logic, the task is therefore to “loosen up the traditional logic in such a way that central problems in it become clear.” (6) These problems, to anticipate, are those of the metaphysics of truth.

Before getting into the matter of logic, Heidegger presents a philosophical framework focused on the understanding-of-Being [Seinsverständnis]; here, transcendence is defined preliminarily as the understanding-of-Being: “human Dasein is a being with a kind of Being to which it belongs essentially to understanding something like Being. We call this the transcendence of Dasein, primal transcendence.” (16) Implied here are comporting-towards and thrownness-onto-beings.

Logic bespeaks laws of thinking. But being governed by laws is a specific constitution of Dasein. Law-abiding presumes the possibility of not abiding, that is, presumes freedom. (18)

The logical tradition absorbs Being to Being-thought, i.e., into intelligibility and thought-determinacy. (28) This tendency is visible in Leibniz; the project is to free logic from its bond with metaphysics and thereby to make logic autonomous.

In Leibniz, this tendency is observed in the definition of truth as identity: “in every statement the [logical] subject must contain the predicate in itself, whether explicitly or implicitly.” (32) Hence every relation of Being is conceptual, i.e., reducible to what is “contained” in the concept of the predicated subject. All hidden identity must in principle be reduced to explicit identity (A is A). To claim B of A is therefore to include B in the concept of A. (33) The logical subject is a host of applicable (included) predicates; but this also implies that all beings, as substances, are pre-determined completely, as what is included in their concepts must be fixed in advance. (34) This is claimed regardless of whether human knowledge is capable of exhausting the predicates “contained” in the subject. (39) It is already obvious here that what Leibniz says about logic presumes metaphysical theses about in what way beings are, what the knowledge of them is like, etc.

This account of truth seems more readily applicable to a priori, necessary truths [veritates necessariae], also called “truths of reasoning”—for example, mathematical truths. The main difficulty with the account consists in the explanation of “contingent truths”, the truth of created beings in time—“truth of fact”. To “attribute to them as well an ideal absolute certainty and truth” means to “assimilate as far as possible the veritates facti to truths of reasoning.” (43) Such is accomplished in a progressive reduction in infinitum, and this in God’s knowledge [scientia Dei] alone. God, as the absolute measure of the finite, human cognition, “thinks the totality of what is possible,” i.e., “that which in actuality is not yet but will be.” (43-44) To include all possibilities, therefore, God’s knowledge must include them as actualities. God does not ‘get to know’ anything; he has already articulated the totality of possible beings in his actuality. (44)

Underlying this account of God’s knowledge is a modelling of perfect knowledge after the present intuition [praesens intuitus], where “present” means, not the momentary ‘now’ of time, the nunc fluens, but eternity, the nunc stans. For only such a compressed ‘now’ admits of the full determinacy of beings; a momentary ‘now’, by contrast, is intrinsically finite and partial, therefore incapable of complete knowledge. (45)

God does not know possible statements “in the mode of composing and dividing,” because that would make knowledge successive, which is a mark of finitude. A human knower, by contrast, must “render what is known separately into a unity by way of composing or dividing in the formation of propositions.” (47) The articulation of a being in finite knowledge takes time and is contingent; unity is added a posteriori to contingently discovered aspects of the being.

It is the definition of truth as identity which, in the case of contingent truths, demands sufficient reason for the truth. This is why the principle of sufficient reason is subordinate to the principle of identity in Leibniz. (55) Let us examine more closely the idea of knowledge underlying this definition of truth as identity and inclusion. God’s “constantly present intuition has its intuited object—the whole of what actually has been, in now, and will be—lying before it as present [anwesend].” (58) Such is the full-fledged idea of permanent presence, observable, for example, in the idea of spatiotemporal continuum. Here, eternity is an implication of simplicity and immutability: God’s knowledge must be “all at once” [totem simul]. (Ibid.)

Leibniz goes into a distinction of knowledge: knowledge can be obscure (not identifying the correct object) or clear; clear knowledge can be confused (with rules of distinction that are themselves not clear) or distinct; distinct knowledge can be inadequate (where the marks are clear but not distinct through and through, i.e., ‘tenuous’) or adequate; adequate knowledge can be blind/symbolic (where the view of marks “individually and as a whole” is not attained but substituted by signs) or intuitive (most perfect). (59-63) The following diagram shows the bifurcations:

Phenomenologically, the distinction between adequate and inadequate knowledge is the most important. Adequate knowledge is fully detailed, which would already be an ideal for finite knowing. Within adequate knowledge, Leibniz makes a further distinction with respect to how the completely analyzed being is appropriated. With the discussion about the completeness and the appropriation of knowledge, Leibniz reforms Descartes’ conception of truth as being perceived clearly and distinctly: he says that “to be true is equivalent to being adequately perceived by intuition.” (67-68) But this move of Leibniz seems at odds with his own definition, in logic, of truth as identity. It seems that what matters here is not the identity to which all judgments are eventually reduced (as is the case in logic), but rather “the total grasp of the harmony of multiplicity” [compatibilitas], which is about the way a judgment is reduced to identity. (68) Identity, in this case, cannot mean “an empty uniformity stripped of difference”; it must mean “the entire richness of real determinations in their compatibility without conflict.” (Ibid.) Despite this insight, Leibniz tries to deduce identity in the sense of unified multiplicity from empty, formal identity, so that the principle of identity remains prioritized in logic.

At this point, Heidegger raises two questions. First, what must the Being of beings look like if truth were to be identity? Second, what exactly is intuited in adequate knowledge? This leads to him to Leibniz’s monadological interpretation of Being. The monad is “that which simply originally unifies and which individuates in advance.” (73)

Descartes’ construal of physical beings as extendedness [extensio] dissolves individual beings into indifferent ‘points’. A point is merely negative, and it cannot unify a whole because it is itself in need of unification. (75) To avoid this difficulty, Leibniz looks for a source of intrinsic unity. This he finds in monads or “formal atoms”, reviving the Aristotelian notion of substantial form: these are “the primordial indivisible principle of formation,” (77) indivisible because they unity actively.

But the meaning of “active” is very subtle here. Leibniz distinguishes between actus in the sense of actio (the power to accomplish) and actus in the sense of forma (the capacity to undergo; inclination towards; aptitude). While the former moves entirely within the plane of actuality, the latter (which would belong to affectivity, receptivity, and passivity in post-Kantian thought) designates a ‘not-yet’; it is the very condition of actualization. (81) More precisely, inclination or aptitude is not merely a predestined ‘not-yet’; it is rather creative out of itself (conatus). Heidegger identifies this with drive [Drang], which already presumes a self-structure in taking something upon oneself. (82) Drive “requires no prior external stimulus” and is always on its way to releasement. (Ibid.) All it needs is removal of existing impediment, i.e., Schelerian “de-hindrance.” (83; Cf. Sartre’s “initiative”.)

While Heidegger sees this creative and affectively spontaneous drive-structure only in the selfhood of Dasein, Leibniz applies it to all beings (monads) for the sake of their respective unity of multiplicity. (83) The result is that the Being-together of beings can only mean indirect mutual limitation: “no substance can confer its drive, which is its essential Being, on other substances. It can merely impede or not impede, and even this function it can exercise only indirectly.” (83) The influence between substances (monads) must be indirect, because the impeded substance must have prepared for this impediment in its own affectivity—a preparation which can only be placed in the substance by God in advance.

It is for this reason that each monad must already bring in itself the entire universe. (84) But “What unifies must anticipate by reaching beforehand toward something from which every manifold has already received its unity.” (90) A manifold can be unified originally only when a field is anticipated for them.

Thus, from the Leibnizian drive, Heidegger derives his own notion of transcendence, applicable in his case to Dasein alone: “a structurally antecedent reaching and gripping.” (90) Transcendence is necessarily ecstatic. Moreover, in order to unify a multiplicity, drive must “have already surpassed and overcome multiplicity”: this is summarized as its “world” character. (91) A horizon of unified multiplicity precedes actual, multiple things. What undergirds this horizon is time. (92) Finally, drive is always finite and local—that is, unifying from a ‘point’ (individuating and individuated apperception). (95) Finitude entails resistance and partiality. (98)

There is an interpolation in Heidegger’s explication of drive, which is about Leibniz’s generalization of the concept to the entirety of beings, an unwarranted move according to Heidegger. Heidegger argues that what Leibniz says about drive is derived from our own mode of Being, from the experience of the self. (85-86) The dynamicity Leibniz finds in drive comes from the activity of one’s self-understanding. In a Cartesian vein, for which Being-thought is isomorphous and coextensive with Being, Leibniz attributes the dynamicity he finds in Dasein’s self-understanding to the totality of beings. (87)

By contrast, Heidegger submits that there is no transcendence without the transcended. The structure of transcendence is binary and irreducible to the dynamicity of drive. Even the notion of drive falls short because it remains ontic. To predicate every being with drive would then constitute a “universal animism by analogy with the ‘I’.” (88)

To summarize, reduction to identity in logic is possible, only when ontologically “Being itself is constituted by an original unity,” seen “in the monadic structure of substance.” (102) Thus, logic has a metaphysical foundation.

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Heidegger moves on to clarify this foundation. His first step is to examine the principle of sufficient reason. He emphasizes the “rather than” [potius] in Leibniz’s formulation of the principle: there is a reason why anything exists rather than nothing; there is a reason why this exists rather than anything else; there is a reason why it exists in such a way rather than in another way. (114) The principle is thus one of preference.

After referring propositional truth to primordial disclosure according to Dasein’s concern, a topic already exposed in Being and Time, ¶44, the discussion focuses on clarifying transcendence in relation to intentionality. First, transcendence is not a subject-object relation added a posteriori to the extant terms of the relation. Relatedness belongs to subjectivity as such. (129) Second, while Husserl de-psychologized Brentano’s concept of intentionality and purged the representationalism it once implied, intentionality was nonetheless explained as “meaning” [Meinen], which is a neutral characteristic of knowing. “All intentionality is first a cognitive intending, upon which other modes of active relation to beings are later built.” (134) Thus, intentionality is only an ontic transcendence, possibly only on the basis of original transcendence, i.e., the Being-in-the-world of Dasein. (135) The idea here is that an understanding-of-Being prepares a clearing [Lichtung]; it “first secures the possibility of beings manifesting themselves as beings”; it “bears the light in whose brightness a being can show itself.” (Ibid.) Understanding-of-Being is a unitary phenomenon here; it is not a property of Dasein; nor does it presume Being as extant.

To distinguish original transcendence from ontic characterizations of it, Heidegger feels it necessary to revisit, in §10 of the lectures, the central themes of Being and Time. He makes a clarification about the “neutrality” of Dasein, emphasizing that it is not indifference but a structural precondition of differences. (136) The isolation (individuation) Dasein implies is not factical-existentiell but metaphysical. Isolation here means particularization in locality. (137)

Moreover, “Dasein harbors the intrinsic possibility for being factically dispersed into bodiliness and thus into sexuality”; “the authentic concreteness of the origin “consists in “the not-yet of factical dispersion [Zerstreutheit].” (137) For Heidegger, multiplicity can only be understood on the basis of this dispersion. This distinguishes him from Levinas, Deleuze, etc. Since dissemination [Zerstreuung] is essential to Dasein, focusing on un-concealing a particular object is always at the price of concealing the rest. Thrownness into the multiplicity of nature is fundamental for being governed by nature. (138)

Finally, “attaining the metaphysical neutrality and isolation of Dasein as such is only possible on the basis of the extreme existentiell involvement [Einsatz] of the one who himself projects.” (140) This justifies the invocation of authenticity, Being-towards-death, and conscience in Being and Time. What is highlighted here, though, is the existentiell involvement rather than the particularity of the person. (Ibid.)

Here, the investigation is directed further into time. “The understanding-of-Being stands in a primordial relation to time.” (141) This concerns, not ontic time, but “the first dawning of the real metaphysical problem of Being as such.” (142) “The Being of beings gets understood by reference of time.” (144)

The analysis focuses (in line with the foregoing interpretation of Leibniz) on the Aeion, that which is there “at any time”. The constant duration of Aeion is traced to what is “at hand anytime for everyday use,” what is “immediately and for the most part always present [Anwesende].” It is proximity and immediate availability, not eternity, which really matters in the notion of presence; the temporal is shown as underlying the extra-temporal. (145)

Then, the temporality of the apriority of Being is interpreted as ontological (neither ontic nor logical): it is what we always already understand, so that we address what we know “with regard to its Being.” (147-148) These are obscured in an ontology of extant objects. (150)

Then comes the claims that may be read as what William Blattner in Heidegger’s Temporal Idealsim (1999) called an “ontological idealism”: “Being ‘is’ not, but Being is there [es gibt], insofar as Dasein exists. […] only insofar as existing Dasein gives itself anything like Being can beings emerge in their in-themselves.” (153)

We shall note here that “what is Dasein?” may not be the proper question; the whole problematics is transcendental, and an ontic being like Dasein cannot serve as the transcendental condition for the possibility of Being. What matters is the “existing” of Dasein, which is not ontic Being-extant or presence [Anwesenheit] but an ecstatic structure of transcendence-freedom. Like the Being thus made available, Dasein (genuine subjectivity) is vanishing; they ‘are’ [geben sich] “when they give access to beings.” (Ibid.) It is this vanishing that is properly Temporal about Being and Dasein; it keeps these concepts with the Kantian bounds of possible experience and resists a merely ontic conception of Dasein.

§11 of the lectures is a thematic explication of transcendence. Epistemological and theological transcendence are both problematized, while ontological transcendence is interpreted as “the primordial constitution of the subjectivity of a subject. […] To be a subject means to transcend.” (165) Since transcendence is not accidental, Being-in-the-world is the basic constitution of Dasein.

Accordingly, what gets crossed over is not a barrier between the subject and the object, rather, the being itself becomes manifest on the basis of transcendence. The being is thus set in opposition [gegenstehen] and is manifest ‘in itself’, not as dependent on Being-known. (166) The ontological transcendence of Dasein enables its factical embeddedness in nature. (Incidentally, in Merleau-Ponty it is the reverse: the factical embeddedness of Dasein in nature enables its ontological transcendence.)

While the being is surpassed in transcendence, the towards-which of this surpassing is the world. Dasein’s factical existence is based on its essence as Being-in-the-world (169)—a formula clearer than Sartre’s “facticity”. While clarifying the notion of world itself, Heidegger refers to the Greek concept of cosmos: it means, not the collection of beings, but their condition [Zustand]: “this particular condition of beings, this world of beings in contradistinction to another.” (171) In brief, “world” designates the ‘how’, the organization or configuration of beings: “the totality, the unification and possible dispersal of beings.” (172)

From this, Heidegger interprets what determines the ‘topography’ of the world, the Platonic “good” [Agathon], as the for-the-sake-of-which [Worumwillen]. (184-185) Hence freedom as the purposive for-the-sake-of characterizes essentially the transcendence that “worlds” [weltet] a world. There is a voluntarist undertone: the organizing principle is referred back to a singular willing freedom. Though egoicity [Egoität], as selfhood and freedom, is distinguished from existentiell, ethical egoism, as the former undergirds both egoism and altruism (187), it remains true that in-each-case-mineness [Jemeinigkeit] is key to transcendence and freedom. The “metaphysical isolation” remains, though it becomes less clear whether Dasein in this case can only converge with an individual. (188) It seems that any being with a reflexivity (“to be fundamentally towards oneself”—189) and a self-other dichotomy (190) would do (for example, a self-asserting community).

We may approach this difficulty from another perspective, i.e., from the subtle sense of freedom at play here. It does not mean primarily “self-initiating spontaneity” as opposed to “a compulsive mechanical sequence.” (191) It means rather a capability for binding commitment, which makes the world a “counter-hold of Dasein’s for-the-sake-of.” (192) This means freedom opens up a space of possibilities in which actual beings may emerge as restriction. Only because Dasein as freedom is excessive (striving for more) can it be limited, i.e., restricted to ‘less’. This allows Heidegger to make a case similar to what Sartre said about the prisoner: “this completely factical lack of freedom is itself an elemental testimony to transcendence, for despair lies in the despairing person’s vision of the impossibility of something possible.” (193) The space is already opened up for this despair to make sense. The for-the-sake-of of free transcendence allows for the world-entry of beings. (Ibid.) “World-entry happens when transcendence happens, i.e., when historical Dasein exists.” (194) Such is the event [Ereignis] as Heidegger later calls it.

In world-entry, extant things undergo ‘nothing’. This nothing is not a nihil negativum; it is Being and must be clarified in terms of time: “the intrinsic possibility of transcendence is time, as primordial Temporality [Temporalität]!” (195)

The task here is thus to interpret Temporality as a nihil originarium. The exposition focuses on the ecstatic and horizonal characters of time. Regarding the former, what becomes manifest in saying “now” is the relation of the ‘now’ to what occurs; time thus withdraws from the scene: “the now itself guides and pushes us forward to that which is just transpiring there in the now” (200); it vanishes into the unfolding of the event. Here, the unthematic character of time (Cf. GA21) is linked to its ecstatic character; a ‘now’ or ‘then’ arises when Being is opened up via a transcending Dasein. (202) It is clear that the ecstases are not ways we access pre-existent temporal dimensions; they are the origin of those dimensions. (203)

This constitutes a critique of Husserl’s phenomenology of inner time-consciousness but also leaves room for further criticism. We need to take this warning: “time ‘is’ not, but rather temporalizes itself. Thus every attempt to fit time into any sort of Being-concept must necessarily falter” (204)—including the Being-concept of consciousness [Bewusst-sein]. Moreover, “the unity of the ecstases is itself ecstatic”; Dasein is not a stable core of time but an oscillation. (207)

On the other hand, though the ecstasis does not produce a definite possible, it does produce “the horizon of possibility in general, within which a definite possible can be expected.” (208) The horizon is nowhere; it ‘is’ not but temporalizes itself; it is the ecstema—the correlate of ecstasis. The unity of horizons even precedes the unity of ecstases. If so, how can a horizon still be “produced”? Here we are at the limits of transcendental philosophy.

The conclusion is that “time is essentially a self-opening and expanding into a world.” (210) But Heidegger is not sure whether this finding with Dasein can be made universal-ontological. What we know is that Dasein gives us a sense of what it means to temporalize (unfold), which in turn makes comprehensible the nihil originarium—of the world and of time.

The final section of the lectures develops the idea of ground from the for-the-sake-of. (213) The search for ground is Dasein’s freedom for the ontic. (213) From this grows the resistance of beings as the powerlessness of Dasein—thus it must look for a ground. The domination of nature does not remove, but proves, this metaphysical powerlessness; the search for ground betrays Dasein’s groundlessness. (215)