Heidegger’s strategy for debunking the problem of the external world on the basis of an ontology of Dasein is questionable because of a fundamental am-biguity in the very notion of Dasein, and, indeed, in the “question of being”
that informs Being and Time. In one sense, the question of being aims at de-veloping regional ontologies, such as the ontologies of nature, of Dasein, of life, or of space-time, and so on, by spelling out fundamental concepts for ar-ticulating these regions.30 In the context of regional ontology, Heidegger means by “being” the particular mode of being of entities belonging to a spe-cific ontological region. Since Dasein is characterized by self-interpretation, the method of the regional ontology of Dasein is the method of hermeneutic phenomenology. In my Heidegger’s Philosophy of Being (1998), I called this the
“phenomenologico-hermeneutical leitmotif ” in the question of being.
In a second sense, the question of being is a transcendental question.
Heidegger holds that the being (Sein) of entities is determined by Dasein’s understanding of being (Seinsverständnis), and he compares the “philosophi-cal phenomenon” of being with Kantian transcendental structures.31In the context of this “transcendental theme,” Heidegger means by being a holis-tic transcendental framework that is somehow constitutive for the way in which entities appear to us, and he holds that being in this sense depends upon Dasein, that is, upon Dasein’s understanding of being.
The fact that the ontological analysis of Dasein is both a regional ontol-ogy and a transcendental philosophy renders the notion of Dasein ambigu-ous. Dasein not only is “the being that we ourselves are,” as Heidegger says in section 2 of Being and Time, but Dasein also is the transcendental agent in us.32 Furthermore, whereas Dasein in the sense of regional ontology is merely one ontological region among others, Dasein in the sense of tran-scendental philosophy is unique and more fundamental than any other on-tological region, because it somehow constitutes these other regions. Ac-cordingly, the transcendental philosophy of Dasein develops “the conditions for the possibility of any ontological investigation.”33
We might say that the phenomenologico-hermeneutical leitmotif in the question of being is its pole of plurality, because it aims at articulating the many senses in which “being” is said (there are many ontological regions), whereas the transcendental leitmotif is its pole of unity, because all notions of
“being” are transcendentally reducible to Dasein’s understanding of being (Seinsverständnis). Hence, Heidegger’s question of being has a bipolar structure Heidegger’s “Scandal of Philosophy” 177
similar to Aristotle’s question of being.34If this is correct, there is one global interpretative issue that should be resolved if we want to assess the philo-sophical viability of Heidegger’s debunking strategy. Does Heidegger want to show that the problem of the external world is meaningless by a regional ontology of Dasein, by a transcendental philosophy of Dasein, or by both? More in particular, one might distinguish four areas of interpretative problems:
A. One cannot doubt that there are transcendental arguments in Being and Time. According to Heidegger, the “Being” (Sein) of things depends upon Dasein’s “understanding of the Being” (Seinsverständnis) of things.35In other words, the “subjective” conditions for understanding being, such as the orig-inary temporality of Dasein, are also “objective” conditions for being. In the past, all such transcendental theories turned out to imply a specific variety of the problem of the external world: the problem of the Ding an sich (sec-tion 1, above). We may wonder how Heidegger can be a transcendental philosopher and also claim that he eliminates this problem (instead of pro-viding some solution to it). How should we interpret Heidegger’s attempt to reconcile the “no problem” view with the “transcendental” view? Does Heidegger succeed in reconciling them?
B. The first problem area condenses, as it were, into a number of passages in the text of Being and Time, which David Cerbone has aptly called “puzzle passages.”36Here are two of them:
(1) Being (not entities) is something which “there is” only insofar as truth is. And truth is only insofar as and as long as Dasein is.37
(2) Entities are, quite independently of the experience by which they are disclosed, the acquaintance in which they are discovered, and the grasping in which their na-ture is ascertained. But Being “is” only in the understanding of those entities to whose being something like an understanding of Being belongs.38
In these puzzle passages, Heidegger tries to reconcile some version of “en-tity-realism” with some version of “being-idealism” (being “is” only in the understanding by Dasein).39But how is that possible, if “being” is defined as
“that which determines entities as entities, that on the basis of which enti-ties are already understood, however we may elucidate them in detail”?40 The solutions of Kant and Husserl consisted in a combination of empirical realism regarding entities and transcendental idealism regarding constitutive structures (“being”). However, both solutions implied that empirical entities are transcendentally constituted, so that, on the transcendental level, there is entity idealism with regard to empirical entities. Furthermore, both solu-tions raised the problem of the Ding an sich, the existence of which was af-firmed by Kant and denied by Husserl.41What solution does Heidegger 178 Herman Philipse
propose? How can Heidegger reconcile his solution with his claim that the problem of the external world is meaningless?
C. In section 3, above, I argued that Heidegger’s strategy for debunking the problem of the external world is superior to the strategies of Carnap and Moore. However, this apology for Heidegger is seriously incomplete. We saw that both Moore and Carnap failed to address the reasons for external world skepticism, reasons which derive predominantly from a scientific analysis of matter and perception. Does Heidegger fare better in this re-spect, so that his analysis is superior on this point as well? In section 43a of Being and Time there is a passage in which Heidegger diagnoses the source of external world skepticism as follows:
Our task is not to prove that and how there is an “external world,” but to point out why Dasein, as being-in-the-world, has the tendency first to annul “epistemologi-cally” the “external world” in order to prove it afterward. The cause (Grund) of this lies in Dasein’s falling and in the way in which the primary understanding of Being has been diverted to Being as occurrentness—a diversion which is motivated by that falling itself.42
But this passage is not sufficiently clear. In particular, it is unclear why Hei-degger thinks that what he calls Dasein’s falling (Verfallen) is the cause (Grund) of external world skepticism, and why analyzing this cause will re-fute the arguments for external world skepticism. An interpretation of Hei-degger’s strategy for debunking the problem of the external world has to clarify this point.
D. A final area of difficulties consists of Heidegger’s pronouncements on the Ding an sich in Being and Time. Within the global horizon or framework of the world, Heidegger distinguishes between a number of more deter-minate frameworks in terms of which we may interpret the entities that we encounter.43Two of these frameworks are discussed in Being and Time, the framework of being ready-to-hand or being serviceable (zuhanden) and the framework of being present-to-hand, extant, being occurrent, or being pres-ent (vorhanden). Other frameworks are merely mpres-entioned, such as the frame-work of nature as that “which ‘stirs and strives’, which assails us and enthralls us as landscape.”44Now Heidegger writes repeatedly in italics that “Readi-ness-to-hand is the way in which entities as they are ‘in themselves’ are determined ontologico-categorially.”45This is surprising, for in the Kantian tradition, enti-ties are said to be an sich if they are ontologically independent with regard to the (transcendental) subject, whereas equipment and other entities that are ready-to-hand (zuhanden) are implausible candidates for this position.
Why, then, does Heidegger claim that readiness-to-hand (Zuhandenheit) is Heidegger’s “Scandal of Philosophy” 179
the way things are an sich? The fact that the relevant statements are italicized proves their importance for the interpretation of Being and Time.
Since the text of Being and Time is unclear at many crucial points, substan-tial interpretations of Heidegger’s strategy for debunking the problem of the external world will be underdetermined by the texts. For this reason we must evaluate the existing interpretations by a comparative analysis and in-quire to what extent they satisfy a number of criteria for theory-choice.
With regard to the interpretation of philosophical texts, the two most im-portant criteria for theory-choice are: (1) the criterion of historical textual adequacy, and (2) the criterion of philosophical fecundity. Is it possible to develop an interpretation of Heidegger’s strategy that solves the problems of areas A–D, above, and that is both textually adequate in an historically plau-sible way and philosophically fruitful?