CHAPTER 7

On the Roots of Rationalism: Strauss’s Natural Right and History as Response to Heidegger

But it is the essence of prudence that one know when to speak and when to be silent. Knowing this very well, Locke had the good sense to quote only the right kind of writers and to be silent about the wrong kind, although he had more in common, in the last analysis, with the wrong kind than with the right.

LEO STRAUSS, Natural Right and History

I. THE UNNAMED OPPONENT

Leo Strauss’s Natural Right and History (1953) is an introduction to political philosophy through a historical treatment of natural right. “Natural right claims to be a right that is discernible by human reason and is universally acknowledged” (9).¹ Strauss seeks to restore knowledge of “the problem of natural right,” which is “today a matter of recollection rather than actual knowledge”(7). He is careful not to identify the philosophy of natural right with political philosophy as such or even classical political philosophy. Political philosophy itself is older than any doctrine of natural right and indeed “seems to begin” with arguing for “the conventional character of all right” (10). But for the classical political philosophers, both adherents and opponents of natural right, “the distinction between nature and convention is fundamental. For this idea is implied in the idea of philosophy”(11).²

The modern “historical consciousness” denies “the premise that nature is of higher dignity than any works of man” (11), and in assuming that all human thought is historical, rejects “the idea of philosophy as the attempt to grasp the eternal,” which is the fundamental premise of ancient conventionalism as well as of natural right doctrines (12). Strauss asserts that “our most urgent need” is to understand the issue between historicism and nonhistoricist philosophy (33),³ for historicism in its philosophical form questions the possibility of philosophy, a possibility that is “the necessary and not sufficient condition of natural right” (35). What Strauss calls “radical historicism” (also “‘existentialist’ historicism,” 32) assumes that

philosophy in the full and original sense of the word, as the attempt to replace opinions about the whole with knowledge of the whole, is not only incapable of reaching its goal, but absurd, because the very idea of philosophy rests on dogmatic, that is arbitrary, premises or, more specifically, on premises that are only ‘historical and relative.’ (30)

The first chapter (“Natural Right and the Historical Approach”) contains a summary (30–31) of “the most influential attempts to establish the dogmatic and hence arbitrary or historically relative character of philosophy.” According to this thinking, the tradition of philosophy dogmatically assumes that the whole is intelligible, and consequently identifies the whole as it is in itself with the whole in so far as it is intelligible. It thereby assumes the equation of “being” with “object,” that is, with what can be “mastered by the subject.” Further, the whole is thought to be unchangeable on the basis of “the dogmatic identification of ‘to be’ in the highest sense with ‘to be always.’” Against these dogmatic assumptions and claims, radical historicist thinking puts forward the discovery of the historicity of the whole: the changing, incompletable, unpredictable character of the whole and the essential dependence, accordingly, of human thought on “something that cannot be anticipated or that can never be an object” mastered by the human subject. Thus “‘to be’ in the highest sense cannot mean—or, at any rate, it does not necessarily mean—‘to be always’” (31).

Informed readers today cannot fail to see that Strauss’s summary is an account, albeit in some ways peculiar, of the thought of Martin Heidegger, none of whose works is cited and whose name is not once mentioned in the book. Strauss disavows any engagement in the present discussion with the unnamed author or authors of the doctrine compressed into a few pages; he claims that “we cannot even attempt to discuss” the most fundamental theses of radical historicism (31). When Strauss wrote his book Heidegger was barely known as a thinker in this country but was already notorious for his endorsement of Nazism while rector of the University of Freiburg and on occasions thereafter. The argument of Natural Right and History, in its foreground and not only there, is oriented toward the contemporary social sciences and a public-spirited discussion of the foundations of morality and law (8). Strauss had more than one ground for thinking he could not afford Heidegger a comfortable and well-lit abode in this setting. Even so, his first chapter exposes the elements—in Strauss’s manner of laconic and mostly implicit argumentation—of a philosophical critique of Heidegger that is developed through the rest of the book. Taken as a whole the book lays the basis for a full confrontation with the thinker whom Strauss regarded as the one great philosopher of the twentieth century.⁴ I will offer some observations about those elements and make some suggestions about the larger argument about Heidegger to which they point.

II. HISTORICISM’S UNSTABLE PREMISES

The radical historicist challenge to philosophy emerged when historicism “suddenly appeared in our lifetime in its mature form” as a “critique of human thought as such”; nevertheless an earlier historicist critique of natural right played an important role in radical historicism’s formation (12–13). The crisis of natural right in the eighteenth century, from which emerged the historical school of jurisprudence, led ultimately to radical historicism (34). Strauss would show that the “experience of history,” which the historical school claimed to discover, is still assumed, without examination, by radical historicist thought (22, 32–33).⁵ In particular, radical historicism has not examined whether the said “experience” is not the outcome of two beliefs, the first of which it avowedly rejects: the belief in necessary progress and the belief in the supreme value of diversity or uniqueness (22). Strauss says we need an “an understanding of the genesis of historicism that does not take for granted the soundness of historicism” (33). He argues, in effect, that radical historicism is undermined by its failure to have adequate historical awareness of its own premises. It fails by the very standard of analysis it respects, knowledge of historical origins. What it especially fails to uncover is the shaping of the “experience of history” by the “politicization of philosophy” since the seventeenth century, an event that is the presupposition for the fact that a crisis in political philosophy (the crisis of natural right) “could become a crisis in philosophy as such” (34).⁶

The thought of the historical school is taken as a “convenient” starting point for this critique (13), but its philosophical sources—sources comparable in theoretical weight to Heidegger—are Strauss’s chief concern. Two are prominently mentioned, more or less corresponding to the two beliefs that combine in the “experience of history”: Rousseau as questioning the naturalness of the universal in the name of individuality (14–15), and Hume and Kant as criticizing theoretical metaphysics for the sake of the final securing of practical life against speculative subversion (19–20). Historicism shares with “the tendency of men like Rousseau” the view of the higher value of the local and temporal, and with Hume and Kant it shares the effort to define the limits of human knowledge within which certainty can be found. Historicist thought combines these in its nonskeptical position that all thought has a nonarbitrary basis in particular historical conditions (20). Like the modern critique of metaphysics it is directed against transcendence (15); historicism’s claim to have discovered an “experience” that discloses the emptiness of all transcendence is explicitly or implicitly a proclamation of the superiority of the thought of the present to all previous thought. Yet this claim is inherently transhistorical and can be consistently incorporated within the historical experience only if interpreted as a nontheoretical commitment (26) or as “an unforeseeable gift or an unfathomable fate” (28). In this way the crisis of early historicism resulted in radical historicism. Yet historicism is from start to finish connected with “divination” (12, 33) and not with theoria.

One already discerns the outlines of a genealogical critique of Heidegger that unfolds in later chapters. The “critique of reason” as the search for certainty within well-defined limits proceeds from Hobbes’s grounding of the “dogmatism based on skepticism” entailing the primacy of practice over contemplation (177n, 319–20). Strauss is centrally concerned with how the Hobbesian move sets the stage for German Idealist philosophy (173–77, 248–49, 272–82); the longest passage of the book on a German philosopher mentioned by name is a discussion of Hegel near the end of chapter 6 (319–21). The primacy of the practical is not overcome but only intensified when Hegel, with some resemblance to Burke, regards human action and its products, rather than the superhuman whole, as the highest theme of philosophy (319–20; cf. 29). The metaphysics of practice, in order to be a completed science, has to contemplate action as completed; history achieves its final telos in absolute knowledge of the logic of history. The Hegelian notion of completed practice introduces a motive for existentialism’s attack on theoretical science (in Kierkegaard and Nietzsche) and for radical historicism’s critique of the metaphysical tradition: the recovery of practice as concern with agenda in a “significant and undetermined future” (320). This is a motive that cannot be derived solely from the problems of the historical school.

The passage on Hegel in chapter 6 thus directs the reader back to the passage on radical historicism in chapter 1, wherein Hegel plays a larger role than seems the case on first reading. The radical historicist account of the history of philosophy runs as follows: metaphysics, as rooted in Greek thinking about Being (and culminating in Hegel, one may now add on second reading), assumes that the future of the whole can be predicted or that the whole is complete. This view of the whole is a consequence of the Greek identification of “to be” with “to be always,” an identification made in accordance with a hidden presupposition in Greek thinking that disregards anything that cannot be an “object” mastered by the human “subject” (30–31). But the incompletability and unpredictability of human action belie this view of the whole: “the whole is actually always incomplete and therefore not truly a whole” (30–31, 320–21). Radical historicism claims to surpass both modernity and modernity’s roots in antiquity; its attack on modern speculative philosophy of history is not a return to the premodern view of history as a sphere of contingencies, for it retains the modern assumption of the superiority of practice to theoria. And without theoria, or the grasp of the universal transcending the present, there can be no prudence (321).

Thus radical historicism, in treating the realm of contingent and incompletable practice—what it calls “the temporality of Dasein”—as the “horizon” from which Being is to be understood,⁷ carries forward the modern limitation of human thought to the practical, with a deeper attack on theoretical metaphysics. Its account of theoretical metaphysics is profoundly informed by Hegel, both negatively (opposing his “completion of practice”) and positively (practice remains the highest theme of philosophy).⁸ It therefore is akin to the historical school, which has no substantial critique of metaphysics, but which all the same “acted as if it intended to make men absolutely at home in the world” (15) and rejected universal principles as making men “strangers on the earth” (14). However, radical historicism’s effort to establish earthly temporality as the sole human dwelling is unstable, since it has absorbed the Rousseauian thought that the authentic individual cannot be at home in any social world (255, 260–61, 290). Nietzsche, in this regard recalling Rousseau, might have considered the possibility of restoring the Platonic notion of the esoteric character of theoretical analysis, thus rejecting the subservience of thought to life or fate. Strauss observes: “If not Nietzsche himself, at any rate his successors” adopted the alternative of subservience (26). Yet in Heidegger’s thought historical fate at once calls for the rootedness in the particular and for the radical transcending of it: “The attempt to make man absolutely at home in this world ended in man’s becoming absolutely homeless” (18). I shall return to this tension in Heidegger between the longing to be at home and the rejection of all being at home.⁹

III. THE MYSTERIOUS WHOLE: TWO VERSIONS

The critique sketched above, however, offers few inklings of Heidegger’s full significance for Strauss. His account elsewhere of his early attendance at Heidegger’s lectures, and their shattering effect on him and his contemporaries, is hardly compatible with a view of Heidegger as dogmatic antiphilosopher.¹⁰ Indeed central to Natural Right and History is a well-hidden positive relation to Heidegger, which may offer the most crucial ground for not mentioning him, and which lends a deeply ironical character to a book concerned precisely with exposing unexamined historical premises. The thought of a certain “Martin Heidegger” seems to be the unexamined premise of the argument directed against a figure who uncannily resembles him.¹¹

Heidegger questioned in unparalleled fashion the soundness of the tradition of Western rationalism. Such questioning is wholly different from a willful rejection of the tradition.

Certain it is that no one questioned the premise of philosophy as radically as Heidegger. . . . [Jacob] Klein alone saw why Heidegger is truly important; by uprooting and not merely rejecting the tradition of philosophy, he made it possible for the first time after many centuries—one hesitates to say how many—to see the roots of the tradition as they are. . . . Above all, his intention was to uproot Aristotle: he thus was compelled to disinter the roots, to bring them to light, to look at them with wonder.¹²

In a practical sense Heidegger, like many of his contemporaries, began from a certain experience: an overwhelming sense of the collapse of the Western tradition, der Untergang des Abendlandes. But no one else sought for the roots of this collapse with as much analytic power and philological mastery. Surely Heidegger made a case for an essential defect in the Western tradition that had to be taken seriously. When Strauss writes, “I began, therefore, to wonder whether the self-destruction of reason was not the inevitable outcome of modern rationalism as distinguished from pre-modern rationalism,”¹³ his expression of “wonder” implies that the source of self-destruction seemed to him at first to be located plausibly elsewhere—perhaps at the Greek beginnings or in rationalism as such. Heidegger above all others had incited such reflections.¹⁴ Strauss later found another way to reflect on the cause of the collapse when he “concluded that the case of the moderns against the ancients must be reopened,”¹⁵ whereas Heidegger had concluded that modernity was just an extension of the “forgetting of Being” that had befallen the Greeks.

Therefore Heidegger’s thought is not merely the most evident symptom of decline. Specifically Heidegger identified the fundamental presupposition of all rationalism as the axiom that “nothing comes into being out of nothing or through nothing”; he held that “the fundamental principle of philosophy is then the principle of causality, of intelligible necessity” (89).¹⁶ In Socratic fashion Heidegger investigated this premise through an inquiry into that being, the human, which has access to Being or “which is in the most emphatic or authoritative way.” The object of Heidegger’s inquiry is therefore more adequately expressed as the question that inevitably arises for that being which finds itself “thrown” in the midst of beings: “Why are there beings rather than nothing at all?”¹⁷ This question is not a cosmological question about the causal origination of beings out of other beings or the whole of beings. The question would persist even if it were known that the whole of beings is eternal. Therefore natural science can shed no light on the question. The true bearing of the question is on the questioner or, more precisely, on the questioning—on the possibility of questioning. All questioning about the beings presupposes an openness to beings as a whole, a fundamental disclosedness of beings, which cannot be grounded causally in any being or beings, including the highest or most perfect being. All attempts at such grounding suffer from a fatal circularity. Heidegger calls the fundamental disclosedness of beings Sein and claims that Sein so understood must be kept sharply separate from the theme of traditional metaphysics, being qua being or the being of beings (Seienden), which is concerned only with the causal constitution of beings or the cosmological question.¹⁸ In Heidegger’s view the highest themes of the metaphysical tradition—the Good, or the ideas, or nous—remain on the plane of the beings, or of das Seiende.¹⁹

Heidegger purported to uncover a thought that the entire tradition had neglected, and he alleged he was thinking beyond or, as he put it, behind the tradition. It expresses a common misunderstanding to say that Heidegger simply rejected rationalism or the Western tradition; to the end of his work Heidegger thought it necessary to think with and through this tradition, especially its Greek beginnings.²⁰ Furthermore, what he calls the “forgetting of Being” is not a mistake to be set aside but a tendency of thought inseparable from openness to the beings. Human thought cannot stay focused on the mystery of a disclosedness that eludes grounding, and thus there are the inevitable and related tendencies of grounding Being in a highest being (ontotheology) or in the human being (anthropocentrism or “humanism”). For Heidegger these two tendencies are at root the same. Such groundings are always alluring because Being, so far as we know, discloses itself to only one being among beings, the human. Strauss does not share the misunderstanding I mentioned, to be sure. What is more, there is evidence that he believed it necessary to participate in Heidegger’s inquiry; Heidegger’s question is a necessary one, and Strauss’s inquiries are in a sense a continuation of Heidegger’s (31, especially the sentence beginning “It compels us at the same time . . .”; cf. 89). The problems for Strauss arose in the implications Heidegger drew from his question, or the attitudes he adopted toward it. These problems relate ultimately to the absence of political philosophy in Heidegger²¹ and to the connected preference for pre-Socratic over Socratic philosophy.

I offer only a few indications that Strauss might have looked at the Greek philosophers and perhaps especially Socrates with Heidegger’s question in view. Strauss writes:

And Socrates was so far from being committed to a specific cosmology that his knowledge was knowledge of ignorance. Knowledge of ignorance is not ignorance. It is knowledge of the elusive character of the truth, of the whole. Socrates, then, viewed man in the light of the mysterious character of the whole. He held therefore that we are more familiar with the situation of man as man than with the ultimate causes of the situation.²²

There is little basis, if any, in Strauss’s writings for the view that he sought to recover a teleological natural philosophy, or that he thought such recovery a necessary condition for philosophy in its classical form. He thought that the philosopher must come to terms with the unavailability of such cosmology; in the modern era, this means coming to terms with modern science’s failure to provide an account of the human (8).²³ Essentially Socrates faced the same problem with the failure of the cosmologies he knew; his response to that difficulty was his “second sailing,” the dialectical ascent from opinions (122–25). To understand philosophy this way means to acknowledge its unfinishable or aporetic nature (125–26, 29–30).²⁴ And perhaps, contrary to the first impression Strauss gives the reader, Strauss holds that Aristotle conceived philosophy in the same way. (Compare the text at NRH 8 with the citations of Aristotle’s Physics in the note.)²⁵ One also should recall the passing remark in the Hobbes section of Natural Right and History about “the difficulty with which every teleological physics is beset” (172). In sum, I venture to say that Heidegger provoked Strauss (with some mediation by Jacob Klein) to approach Greek philosophy with the suspension of the traditional expectation of finding therein a teleological physics and cosmology. The belief that classical philosophy is inseparable from an “antiquated cosmology” had been a principal barrier against taking it seriously—a belief that Strauss came to see as a misreading of the Socratics.²⁶ Of course, the human must be understood teleologically insofar as it is oriented toward knowledge of the whole, or toward the question of the ground of the whole.²⁷ But this in turn means that the human orientation is toward fundamental and insoluble problems. And thus the philosopher, who is distinguished among humans by the awareness of these problems, is the being that preeminently reflects the character of Being as a whole. “To articulate the problem of cosmology means to answer the question of what philosophy is or what a philosopher is.”²⁸ With suitable changes in language, this is granted by Heidegger. But in Strauss’s estimation the awareness of the fundamental problems liberates the mind from its historical limitations and legitimizes philosophy in its original, Socratic sense (32)—a nonhistoricist sense that Heidegger regards as a falling away from a higher kind of thinking. How does one account for this difference?

IV. PHILOSOPHICAL SEDIMENT

It bears on this question to observe that Strauss draws a subtle distinction between the fundamental problems and “the fundamental alternatives regarding their solution.” In one passage he says simply that both are “coeval with human thought” (32), but a few pages later he adds after “fundamental alternatives” the phrase “which are, in principle, coeval with human thought” (35). This seemingly small change points to the heart of the argument of Strauss with Heidegger.

In the first passage Strauss already modifies his quoted stance on solutions with a remark on “however variable or provisional all human solutions to these problems may be” (32). If solutions are thus variable it is doubtful that they are “coeval with human thought”—although “in principle” they could be. Indeed the “experience of history” derives some of its strongest support from the manifold evidence of this variability. Strauss in fact is quite open to the view that human experience is with respect to the proposal of solutions unpredictable and incompletable. He mentions the possibility that great thinkers might arise in the future—”perhaps in 2200 in Burma”—for whose thought we are quite unprepared. “For who are we to believe that we have found out the limits of human possibilities?”²⁹ It seems to be in a related sense that Heidegger sees human history as unfinishable—in opposition to Hegel—insofar as the perplexity of Being is without end, as long as there is man. This would give support to the claim that “there can be entia while there is no esse,” on the assumption that esse or Sein means the perplexity of esse or Sein. Strauss mentions the assertion of Heidegger with skeptical reservation, it seems, yet without any criticism (32). But for Strauss the permanence of fundamental perplexities is the strongest argument for regarding the whole as complete in the decisive respect: the problems, rather than their solutions, are permanent and not variable. This wholeness, however, is available only on the level of theoria, which grasps the problems as problems (32); insofar as one remains on the level of practice, or of attempted solutions, variability and impermanence must be the dominant experience.

I suggest that in Strauss’s view Heidegger does not distinguish the awareness of the fundamental problem from the historical efforts at solutions to it. Hence for Heidegger the question of Being—which always manifests itself in particular “dispensations”—has itself a historical and variable character, even though he also describes this question as determining the essence of man.³⁰ One could say that Heidegger is oriented toward the fundamental question with the intention of showing how the question as question can provide the practical solution to the problems of human existence; thus he speaks of thinking as piety. Or to put this another way, Heidegger’s remarkable “path of thinking” conflates philosophical reflection on the problematic character of existence with nonphilosophic human concerns for being at home in the world—the world defined by particular languages, customs, poetry, and the gods. In Strauss’s view this necessarily conflates the suprahistorical with the historical, or the philosopher’s being at home in the whole with various ways of being at home in human affairs, in which the philosopher can never be entirely at home. For Strauss this entails that Heidegger does not recognize the natural duality of the human—the duality that Strauss sees as the permanent condition of the human (151–52).³¹ According to Strauss, that duality will come to light only through an analysis of the “natural world” of the prescientific understanding—an analysis that must start with the phenomena of political life as they concern political actors and as they present themselves prior to their transformation by the philosophic and scientific tradition (78–81).³² In his disinterment of the roots of philosophy, Heidegger neglected that analysis by starting with the question of Being and only with that question.³³ Heidegger passed over the primary sources for the required analysis of prephilosophic life, namely, the reflections on political life in the classical authors (79–80). But accordingly Heidegger’s Destruktion of the tradition was, from Strauss’s standpoint, radically incomplete.

The heart of Heidegger’s thought is a longing for the overcoming of the duality of philosophic thinking and of being at home in human affairs, or for an unheard-of transformation of human life. In this hope of transformation Heidegger’s thought seeks to relate itself to the traditions of revelation and to the thought of the East.³⁴ Strauss suggests that even in its later form, in which the resolute willing of Being and Time has been replaced by the patient receptivity (Gelassenheit) in which man is appropriated by Being,³⁵ Heidegger’s thought is based on an act of believing or willing, a stance that is “fatal to any philosophy.”³⁶ This is Strauss’s most fundamental criticism of Heidegger, but it barely surfaces in Natural Right and History.³⁷ Perhaps it cannot be fully articulated without exposing the extent of Strauss’s affinity with Heidegger on the aporetic nature of philosophy. All the same, Strauss’s account in Natural Right and History of the origin of the idea of natural right in the prephilosophic situation—of the “discovery of nature” within the context of the ancestral nomos—provides the indispensable foundation for the criticism (81–119). Indeed this account provides an alternative to Heidegger’s uncovering of the pre-Socratic roots of the tradition. Without the investigation of the political and moral context of the appearance of philosophy, such as Strauss undertakes, the full import of the “question of Being” cannot come to light. The absence of such inquiry in Heidegger necessitates that his conception of the philosophic life is “sedimented,” to use a term of the phenomenologists.

Strauss regards the conflation of philosophic reflection and being at home in the world in Heidegger as typical of modern philosophy as a whole. Near the end of his reply to Alexandre Kojève’s critique of his commentary on Xenophon’s Hiero, Strauss describes this feature as follows:

On the basis of Kojève’s presupposition, unqualified attachment to human concerns becomes the source of philosophic understanding: man must be absolutely at home on the earth, if not a citizen of a part of the inhabitable earth. On the basis of the classical presupposition, philosophy requires a radical detachment from human concerns: man must not be absolutely at home on earth, he must be a citizen of the whole.³⁸

What Strauss here ascribes to the Kojèvian-Hegelian philosopher is a motive that, like the historical school’s rejection of revolutionary efforts at “transcendence,” leads to the identification of the source and the condition of thought (or in the case of Heidegger, of aporia and answer). In Natural Right and History Strauss traces this back to Hobbes and, ultimately, Machiavelli.³⁹ I review now a few points in this account. Strauss understands Hobbes’s new natural philosophy, based on the unification of Epicurean materialism and Platonic mathematicism, as allowing the construction of an island of human intelligibility “exempt from the flux of blind and aimless causation” (173) and, therewith, from skeptical attack on its foundations. A certain wisdom seems capable of permanent actualization, because the question of cosmic support from the larger whole in which the human exists can be viewed as superseded (169–77).⁴⁰ This self-limitation of thought is the ground of Hobbes’s holding an “expectation from political philosophy [that] is incomparably greater than the expectation of the classics” (177).⁴¹ Strauss points to the direct link between this Hobbesian innovation (which has parallels in Bacon and Descartes) and the turn to History as well as the idealist accounts of freedom (for the latter cf. 279, 281):

But “History” limits our vision in exactly the same way in which the conscious constructs limited the vision of Hobbes. “History,” too, fulfills the function of enhancing the status of man and his “world” by making him oblivious of the whole or of eternity. In its final stage the typically modern limitation expresses itself in the suggestion that the highest principle, which, as such, has no relation to any possible cause or causes of the whole, is the mysterious ground of “History” and, being wedded to man and man alone, is so far from being eternal that it is coeval with human history. (176)

This comment, obviously referring to Heidegger, leads to the question of how a conception of the whole as defined by “fundamental problems coeval with human thought” (Strauss) can be much different from a conception of “the mysterious ground . . . coeval with human history” and not relatable to higher causes (Heidegger). But as we have seen, Heidegger treats the manifestations of the problems (or the problem) as identical with history, whereas Strauss, who indeed seems to provide no account of how to attain knowledge of the eternal, regards the problems as suprahistorical. The confidence in this suprahistorical dimension derives from reason’s unchangeable need to concede that the human situation could be grounded in some higher and eternal “possible cause”—although one unavailable to human reason. This further means that for Strauss it is essential for reason or philosophy to reflect on the possibility of that of which revelation speaks, although barring itself from ever speaking of it affirmatively. It is Strauss’s judgment that by remaining mindful of the problem of the ultimate but unknowable ground, philosophy preserves an awareness of the permanent—as permanent perplexity—that emancipates it from the vagaries of history and lends enduring vitality to its thought.⁴²