1 The philosophy of the Enlightenment, as the philosophy of a century whose reference is the image of light and that presents itself based on this lexicon, is, according to Blumenberg's thinking, a fundamental reference for modern European culture. In his work, this philosophy is connected to several perspectives of study—history, philosophy, semantics, hermeneutics—that identify it as thinking endowed with conceptual consistency, thematic originality, and theoretical authenticity.
2 Blumenberg, as interpreter of a culture of reason that is also a reflection concerning its limits, is at once a theorist of the legitimacy  of modern times and also a hermeneut of images that point thought toward the abstract aspect of ideas. Thus, the various epistemological regimes of his thought, focused on the question of the Enlightenment, encounter and cross one another, becoming superimposed. The search for a historic specificity that defines “limits” and the chronological “overcomings” returns back to a philosophical analysis of the modes of thought that characterize the ideas of the eighteenth century as a philosophical discourse of modernity. Moreover, philosophical analysis, while articulating itself with a theoretical scrutiny in the framework of a system of significations, yields to the practice of a hermeneutic that understands these ideas as “personal” orientations and “specific” tropes.  Finally, metaphoric semantics, joined with concepts beyond definitions themselves, take on the figures of the language of Enlightenment culture as a “historically determined” philosophical matter.
3 History, philosophy, semantics, hermeneutics, and linguistics thus contribute to identifying images through which, according to Blumenberg, the Enlightenment translates its certainty and its doubts, its aspirations and its disappointments, by implementing in history a “particular and distinctive” intellectual “style,” in relation to the past. Examples include the metaphors of light, ? of the book,  and of the shipwreck.  These are “absolute metaphors” of the truth, of the legibility of the world, and of the risks of existence and, at the same time, central images of modern culture. Blumberg analyzes the shifts these images make with regard to “signification itself” that characterize Enlightenment thought as a philosophy endowed with a specific orientation toward the future.
“The Enlightenment of the Eighteenth Century”
4 Blumenberg’s entire philosophy is implicated in these analyses. Due to the polysemy of the French term [les lumières], which in history refers to the Enlightenment as a “determinate period,” but which, in sociology and philosophy, refers to a much vaster array of spiritual changes, Blumenberg’s studies are thus shown to be complex and transversal. As a proper noun, les lumières (Enlightenment) characterizes the thought of a determinate century, “the Enlightenment (Aufklärung) of the eighteenth century,”  and as a common noun (enlightenment), les lumières characterizes the general transformations of consciousness that affect human life and lead all individuals to the dynamic of reason. 
5 Combining philosophical anthropology with the history of ideas, Blumenberg thus begins with broad theoretical thinking on the notion of a modern age, and undertakes a historical investigation of its temporal variations. Moreover, defending the legitimacy, the autonomy even, of modern times and of the Enlightenment in particular, Blumenberg, through his radical relativism (which is also a route towards a radical rationalism), takes the floor in the broad discussion raised by contemporary criticism  regarding the nature of modernity and its “pathologies.” With his ideas inspired by a “balanced progressivism,”  distant from grandiloquence as it is from anathemas, he firmly responds to the tenets of the Kulturkritik of the 1920s, since he opposes the theorists of secularization. 
6 Thus, between meditation on the present and study of the past, Blumenberg interprets the philosophy of the Enlightenment, after Cassirer,  as an organic set of various concepts and plural images and as an intellectual process open to perceptible changes, all while remaining consistent with the program to legitimize and defend reason. The philosophy of the Enlightenment, affirming its immanent normativity and forging its intelligibility with help from the forces of the human spirit alone, summarizes the decisive concepts of modernity and expresses its fundamental aspirations, with the promises and the worries of a new world to explore, but also with premonitions of its possible decline.
Genealogy of the Enlightenment
7 “The Copernican revolution” is located at the source of modernity as well as at the base of the Enlightenment. Beginning with his 1966 text, Blumenberg critiqued the Hegelian idea of a purely intellectual birth of modernity.  In his 1975 work, Die Genesis der kopernikanischen Welt, he lays out his interpretation through a reevaluation of the “Copernican revolution” and a new consideration of its consequences in western culture. Based on his theory of “epochal thresholds,” Blumenberg pushes the traditional genealogies to the point of rediscovering, in the synthesis performed by the “Copernican revolution,” the preconditions of the cultural transformations that characterize modernity. The “Copernican revolution,” while being itself the result of certain extra-scientific preconditions, was revealed to be decisive not only in the history of astronomy, where it contributed a radical reversal of the principles and the paradigms,  but also, and with an extraordinary scope, in the “history of European consciousness,” where it produced a “large change in the very determination of the ends and the goals of our reason.” The abandonment of the geocentric cosmos of Antiquity and of the Middle Ages has, for Blumenberg, not only caused a “diminishment of man” (according to Nietzsche’s expression) or led to the wounding of his narcissism (according to Freud’s expression), but also and above all a cosmological and intellectual “uprooting” (Entwurzelung) of his condition. Displaced toward an empty periphery and thrown into the vast solitude of infinite spaces, Copernican man thus finds himself forced to call into question the certainty of his theological primacy and his confidence in a teleological order made to his measure. He is thus aware of the eccentric character of his condition and of the relativism of his knowledge. The difficult lesson of the “Copernican Revolution” is that a new “absolutism of reality” has since then been asserted in its brutal indifference to human reason.
8 However, once made into metaphor through the image of eccentricity, intensified and even “consummated” by that of the shipwreck (“you are embarked,” according to Pascal’s expression), heliocentric cosmology has also performed a radical reversal of the negative image of Copernican man. “A recentering on man” who, finding himself inhabiting an “oasis of life” in the emptiness of the universe, in the end finds himself forced to concentrate on himself, and to attribute decisive importance to his history and situation. Copernican man is moved by the insistence and the provocations of a new theoretical curiosity (“curiositas,” theoretische Neugier)  that asserts the rights of a creative spirit of a new intellectual order in the absence of a cosmic order. Contrary to the traditional paradigm of the sense-perceptible intuition of the universe (Anschauung), this theoretical curiosity constitutes the dynamic force of the Neuzeit and the great challenge of the Enlightenment, but also, Blumenberg adds, their immanent risk.
9 The final conclusion is that “the Copernican revolution,” having become a metaphor, “becomes explicit as the model of modernity  and as the paradigm of self-affirmation.”  Not by virtue of Copernicus’ philosophy in particular, whose anthropocentric humanity could neither have anticipated nor survived the “self-affirmation” of modern man, as Blumenberg writes, but rather because of the extra-scientific influences that Copernican astronomy exerted on the entirety of philosophy and anthropology through its principles and doctrines. The new theory of truth abandons the classical paradigm of adequation and contemplation. It is gaining hold in the form of an ethic of industrious investigation and a gnoseological moment of clarity, which is becoming realized through homogeneous and total cognitive access to reality. The new theory of science is aided by the experience of probing the invisible, and is armed by mathematics to structure reality according to the regularity and the uniformity of natural law in the context of a philosophy of progress. The new cosmology of the incompleteness of nature and of the infinitude of possible worlds places the observer within the very process of observation, leading to an “intensification” of the problem of space and of time.
10 Thus, the protagonists of the Copernican “revolution” are the ancestors of modern times: Copernicus and Kepler, certainly, but especially Giordano Bruno, theorist of the infinite and martyr of its challenges; Galileo, interpreter of a new theory of truth and “would-be apostle” of its defense; and also Newton, eponymous hero of the Copernican universe. They presented an image of the world and a configuration of science radically different from those from the past and decisive for the future, nourished by a new theory of nature and of reason.
11 Blumenberg then gives the floor to Fontenelle, Diderot, Voltaire, Goethe (an ancestor, two protagonists, and an heir to the philosophy of the Enlightenment). These individuals act out the “heroic era” of the Copernican universe, and embody the worries as well as the hopes of modern man, between anguish about the loss of order and happy confidence in a new and ambitious project. On the other hand, Lambert and Kant find themselves “at the limits” of a “never-completed”  Copernican revolution.
12 Sapere aude, according to Horace's imperative reprised by Kant as emblem of the Enlightenment, includes: the autonomy of reason directed by the self-awareness of its forces in search of the “naked” truth that it itself has “laid bare”; the spontaneity of human freedom as exercise of man's unlimited power over the world with the help of the enormous technological potential available thanks to modern science; the intellectual curiosity that goes beyond the passive attitude of admiration and eclectic mirabilia culture, and is supported by the gesture of provocation and challenge of nature, or even its reinvention and recreation; and the tenacious will to amass in a single present moment the totality of knowledge, and to project out its possibilities. These are the key ideas of that era: a “philosophical era” that defines itself consciously through its own self-affirmation and legitimizes itself through a complete anthropologization of all knowledge; a “historic era” that has a “beginning,” whereas philosophers bring into opposition the unlimited power of a homogenous, unique, and atemporal reason with medieval, theological absolutism; and a “completion” coinciding with its “overcoming,” if not with its “failure.” However, “theoretical reason,” after celebrating its greatest successes in the system of thought of immanence, is discovered to be finite consciousness, finally locating itself again as “public” and “pedagogical reason,” which is forced into reflecting on its “limitless requirement of knowledge” and on its role verifying “instances of its passivity and its straying.”
13 This is the fundamental and irreversible turning point of the Enlightenment, as Blumenberg comments, but also the constitutive difficulty of its realization. The Enlightenment, at first “private postulate” of individual thought, is transformed, in time and by philosophy, into the determination of the “public conditions of an era and of a society.” The short-term philosophical anticipation of a triumphal history of pure reason was realized as a method of a critique of pure reason. Blumenberg writes this, having in mind the Kantian reflection on the difficult relationship between the theoretical insistence on an “urgent” realization of the Enlightenment and the historical experience of the slowness of this realization. This tension will only be resolved, he writes, through consciousness of the finiteness of reason, not as resignation or disappointment but as “final and definitive discovery of his own dignity.” 
14 Descartes and Kant thus constitute the terms a quo and ad quem, being the interpreters of modernity understood in its historical signification, which they also personify as two aspects of the mind. The first is author of a method and enactor of a philosophy understood as the crowning of a science bound for infinity by an atemporal morality according to the schema of the final success of reason. The second is the theorist of a critical reason that concludes with self-limitation and self-regulation of its powers under the double legislation of the public and of the private, and the philosopher of a practical reason that rejects the infinite tensions of an understanding without norms and which realizes this infinity not according to the axes of the absolute time of science, but within the variable conditions of the time of life.
“Century of the Enlightenment, Progress of the Enlightenment”
15 “In the first glimmers of the Enlightenment,”  Blumenberg rediscovers Fontenelle, theorist of a philosophy (still a felicitous philosophy) of progress, and enactor of the century's “double strategy,” that is, affirming the legitimacy of natural light and denouncing the obscurantism (Unaufgeklärheit) of the caverns. Nuncio of the progress of reason under the sign of light, Fontenelle is a central figure in Blumenberg's texts. “Proto-philosophe” of the Enlightenment, Fontenelle, who lived one hundred years between two centuries, allows Blumenberg to put his philosophical metaphorology to the test with the culture of the “Great Century,” like that of the “half-Enlightenment” and the “Triumphant Enlightenment, and to thus reconstruct, based on the twists in this same metaphor, a whole section of the philosophy of “human spirit.”
16 “In the principle of the Enlightenment, there is Fontenelle,” Blumenberg writes. It is in the Digression on the Ancients and Moderns that he finds the original formulation of the philosophical theory of the progress of the Enlightenment. Reason acquires a history, marked by successes and conquests: a thoroughly modern history that is written as the infinite accumulation of experiences, and which takes the form of an “exactitude of reasoning” that is hard to acquire, arduous to apply, extremely slow to perfect, but which “always perfects itself”—and infinitely so. Moreover, the virtues of philosophy—precision, exactitude, rigor—seal the pre-eminence of the Moderns over the Ancients, with Descartes located at the historical origin and at the theoretical foundations of modernity. It is this Cartesian reason, beyond even the doctrines of Descartes that, “through its boldness and its courage,” is brought to enlighten men and to dissolve the darkness. This is how Conversations on the Plurality of Worlds describes this emancipation of reason, as a progressive and irreversible enlightenment of the human spirit. Heuristic and pedagogical, reason transposes discovery into instruction, and instruction into confirmation of the conquered luminosity. Reason is not arrogant, however, but urges prudence, the “moderation of a presumptuous curiosity,” and the self-limitation of “theoretical temerity.”
17 “In the principle of the Enlightenment, there is Fontenelle,” repeats Blumenberg in his text devoted to the myth of the cave (1989), where the History of Oracles offers him the possibility of thinking about the Enlightenment based on the cartography of culture that Fontenelle outlines for modern times: reason abandons the hollow and dark places “of stupid people and caverns,” and chooses the flat and lighted places of academies “to rejoice in the universe there.”  As the perpetual secretary of the Académie des sciences, he celebrates it as the privileged philosophical space that organizes scientific investigation beyond the personal virtues of individuals, and makes an “educated view” of nature possible, capable not only of seeing, but also of “seeing well.” With Fontenelle, reason, Blumenberg concludes, became the form of the organization of reason itself that is dedicated to the progress of humanity. If Fontenelle is “in the principle of the Enlightenment,” he is also its master and protector.
18 In the “maturity and the “fullness” of the Enlightenment, Blumenberg finds Voltaire, Diderot, and d'Alembert, theorists of various philosophies of progress from the period, and authors of the rehabilitation of intellectual curiosity as a legitimate exercise of knowledge. With some of their recent ancestors like Jacob Brucker, and some of their contemporaries like Johann G. Sulzer or l’abbé Galiani, the French philosophes offer Blumenberg a vast body of texts against which he tests the intellectual consistency and the theoretical certainties of the philosophical culture of modernity, without forgetting either the difficulties or the variations in the tangible [sensible] fields of science, history, and morality, as in that of the even more tangible field of anthropology.
19 Examining the philosophes in this way, and relating them to the notion of the history of the “progress of the human spirit,” opposing the triumphalism of the progressivist ideology as he does the catastrophism of a certain contemporary criticism, Blumenberg shows the continuity and the solidity of such a notion, while underscoring a series of anomalies that unveil the constitutive tension of the philosophy of the eighteenth century between hope for reason and anguish about time, and between the exercise of intellectual curiosity and the demand for happiness. Blumenberg does not doubt it: the progress of reason in the eighteenth century means “the progress of Enlightenment.” But it is based on these Enlightenment turns of phrase, the various significations of its imaginary realm and the different doctrines of its nature that Blumenberg comes to interpret the difficulties of the theories of the “progress of the Enlightenment,” not as dilemma or as a paradox, but as the effect on the theory of the philosophical translations of the very metaphor of light. Indicative of the exchanges of signification between metaphor and concept, the philosophical lexicon of the light of reason, he writes, is affected in the eighteenth century by the lexicon of science and the arts. ? The era's discussions on the nature of light and on the new calculations of its speed, the recent questions from physiological optics, the application of the method of perspective, the mise-en-scène of lighting: all these elements complicate the image and the metaphorical translations. And if Blumenberg, with the philosophes, continues to consider the theories of the history of the age of Enlightenment based on the “absolute metaphor” of light that is “incomparable” in its “expressive potential,” it is a matter of a light that has lost all reference to the facilitas of natural visibility, and which is manifested through “flashes” in the search that discovers it and the therapy that applies it: in short, the light of “an educated vision.”
20 Based on the definition of reason as natural light, which is an exercise of the human faculties, the philosophes thus authorize, according to Blumenberg, the investigation and the writing of a “history of the human mind” as a theory of the propagation of light, without ignoring, however, the times, the deviations, the refractions and aberrations, and as theory of vision, without forgetting the limits and distances, the defects and the physiological distortions, the integrations, and the semiotic translations.
21 This begins with Voltaire. As a theorist of the belatedness of humanity's enlightenment in the annals of history and of the Enlightenment's time lag, Voltaire insists on the necessity of accelerating their actions, casting a glance at the abyss of time needed by reason in order to think itself in history—an infinitely long time, if the history of the world is conceived according to the disproportionate dimensions of nature. “We have come late in every respect,” he writes, which adds to the regret of the present effort for the past and the determination for the future. “I said it and have said it again. Let us regain lost time.” 
22 But there is also Voltaire, theorist of progress who, weaving together the Éloge historique de la Raison, offers an apology of the history of the truth and celebrates its accumulated heritage through a praise of reason that has finally returned from the darkness to the truth: a reason that is still “dawning,” certainly modest, and possibly even “ignorant,” but capable, however, of constructing its history and conferring meaning and value to it in the world of mores, civilization, and the arts of man. It is this recent history of reason that is in a position to enlighten what is still in the darkness, assuming the processual form of evolution, finally finding its culminating point in the present (“the most enlightened century that ever was”) and its actors among the philosophers (“the flame of reason lighting and directing their conduct”).
23 But there is still Voltaire, theorist of the limits of human understanding. While celebrating the exploits of Newtonian science, the paradigm of all philosophy, the latter still brings the exercise of “intellectual curiosity” into the framework of an anthropology of finitude: according to the logic of an “economic skepticism,” he measures the powers of knowledge against the gains of happiness, and reduces the infinite demands of reason to the measure of the needs of life and the rule of moral action. Would the white book that Micromégas finds in outer space therefore be the harsh response to the insatiable curiosity of man? And would the vehement reproaches of presumptuousness and aridity that the mistress of the Saturnian addresses him after being abandoned  not be a scenic transposition of the tension of Enlightenment between curiosity and happiness?
24 Lastly, there is Voltaire the privileged interpreter of the metaphorical “shipwreck with spectator.” According to Blumenberg, Voltaire, who had himself been in a shipwreck after the flight from Berlin in 1753, summarizes in almost emblematic fashion the tensions of the culture of the Enlightenment between intellectual curiosity and “moral compassion.”  Critic of the impassivity of the Lucretian spectator and of the supreme indifference of the ancient philosopher with respect to the history of men and their shipwrecks, Voltaire valorizes the curiosity of the spectator as a “natural sentiment,” by appealing to all the pathos of morality and to the philosophical duty for truth.  ?The philosopher of the Enlightenment is in no way similar to the insensitive and contemptuous sage of Antiquity. He is “humanity's lover”: a “sensitive” man who is used to reasoning and “knows how to give examples of virtues and moral truth lessons” to spread enlightened opinion rich in rationality and universality.
25 It is, however, the Encyclopédie by Diderot and d’Alembert that advances most meaningfully the philosophical question of the correlation between the different legislations of science, of history, and of society. As the “exemplary instrument of the Enlightenment,”  the Encyclopedia recognizes the legitimacy of modernity through a new theory of the history of reason that is a history of the spread of light, which offers itself as the conscious testimony and the passionate reconstruction of the progress of reason itself. Blumenberg notes that, if the metaphor of light defines, as it does for Descartes, the lexicon of science, it represents, for the Encyclopédistes, with all prudence, the wariness, and the restrictions of a “wise and modest” philosophy of experience, where shadows play their part. The light is clear, but it is also unstable and uncertain, more or less nuanced, more or less direct: its shine does not manage to dissipate all darkness, such that it allows some objects to be seen, some to be merely glimpsed, and others to remain in the shadows. The light of reason being the necessary—but not the sufficient—condition of all visibility, its partner is the universe, which is often a book “of sublime obscurity,”  according to the image suggested by d'Alembert, which Blumenberg underscores and comments on. Amplifying the metaphor of light, he writes in his scholion:
In the labyrinth of the world, the odd flashes can turn us off the road just like they can ceaselessly bring us back to it if we had happened to leave it … The “truth” is doubtful (Zwielichtig) if its regular order does not stem from the method and if its regular location is not in the system. 
27 Through the notion of order, light is thus thought of as something available, but on the condition that it can be distributed by reasoned method and according to a “prudent graduality.”  If the history of the human spirit in its laborious search for the truth dictates the duties of the philosophical struggle, this history also imposes as a condition a firm and progressive education of various peoples, capable of enlightening them, but “little by little,” as d'Alembert wrote to Voltaire in a hesitant and modest reply to his philosophical enthusiasm. 
28 The Encyclopédie finds its place in this project, Blumenberg continues, as the “great recapitulation of all that can be known about the world just like everything that one can do.”  It is the book of the man who intends to enlighten and to enlighten by his own light. At stake is the very possibility of the passage from fact to value. The challenge is the happiness of humankind. The whole Encyclopédie returns back to man, to his powers, to his faculties, and to his programs: hence, legibility is not submission to a writing or to the deciphering of an enigma, but production of meaning stolen from God's jurisdiction and confided to the resources of the “human condition” alone. Knowledge therefore renounces the rewriting or rereading of a divine order: it is not given by virtue of an adequation. It derives its origin from an interpretation, and develops based on a first act of human consciousness, whose reflective understanding is imposed as the point of departure of all knowledge and as the methodological criterion for every science.
29 If the awareness of living through a “revolution” in philosophy justifies the project of an encyclopedia and allows assumed responsibility for it, only radical humanism that supports the enterprise makes its realization possible. Blumenberg then gives the floor to Diderot, who defines the sensualist Cogito of the Enlightenment in order to seal this reflexive beginning of knowledge through the affirmation of the primacy and the autonomy of reason.  In the Encyclopédie, he thus defends the rights and the duties of a sober exercise of reason, and announces the results of an intelligent transformation of nature: what is more, he wants to engage in a responsible action of critique and of enlightened, civil, and political reform of society “for the general interest of humankind.” Blumenberg does not forget it: the progress of the Enlightenment is the modality according to which temporality is inscribed in the genealogy of knowledge, the contingency of a relation of cause and effect, fact in truth, and the event in the virtue and happiness of human beings.
30 It is therefore in the “determination of the modes of public thought” that the necessity of the Enlightenment resides, realized “according to the order of reason” as “self-preservation” of their gains and the distribution of their resources. Blumenberg underscores it several times. But he also underscores that it is there where their private difficulties also reside, along with their slowness, and delays—as well as their risk.
“The Process of Intellectual Curiosity”
31 Retracing back through the chronology, Blumenberg finally cites Maupertuis, one of the first Newtonians in the still thoroughly Cartesian France of 1730–1740, who was leader of the expedition sent in 1736 to Laponia to measure the degree of the meridian there and thus decide the crucial question of the Earth's shape. Despite the dating of his work, which places him in the first half of the century, Maupertuis, an educated man and philosopher, is a central figure of the Enlightenment, whose outline he sketches setting off from a striking beginning and leading to a worrisome consummation. Maupertuis is for Blumenberg the eponymous author of the most audacious and the most significant transformations of intellectual curiosity “like energy from his century,” as well as the privileged interpreter and the author of possible detours from its exercise without limits or rules in the context of a theory of progress. 
32 Maupertuis is a total figure. “As a protagonist,” he lived through the vicissitudes of the personal practice of scientific exploration over the course of the days of his expedition in Laponia, which was as perilous for his life as it was fruitful for Newtonian astronomy; “as a scholar” steeped in practicing rational questioning, he edited the accounts in the form of an “intellectual curiosity” operation; “as a bureaucrat,” he sketched out the catalog of its endless applications in the proceedings of the Academy of Berlin where he presided. But “as philosopher,” open to personal risk as well as to intellectual adventure, he also revealed the excesses of this curiosity, and “as a prophet” he glimpsed its consummation in extreme activity. The Letter on the Progress of the Sciences is the disturbing manifesto of a philosophy of “absolute, imaginative, and productive” curiosity, as Blumenberg defines it, not without fearing its consequences: scientific inhumanity.
33 Blumenberg asserts this with particular emphasis, recapitulating his analyses on the philosophy of the eighteenth century in the double perspective of a light that progressively spreads and a shadow that still remains, hovering. With Maupertuis, he writes, curiosity is no longer manifested as a motive for the philosophical revolt against authority, according to Voltaire's definition. It is no longer defined as an intellectual pleasure, similar to hunting or to playing, according to Hume's suggestions; nor as a work of knowledge capable of making humans “more perfect,” according to Reimarus' wishes. With Maupertuis, intellectual curiosity forgets its origins in amazement and in availability with respect to phenomena. To the contrary, this curiosity becomes vital as a will to invention and effort at conjecture, in the “high-style” Faustian project of reconstituting the perfection of nature through the exercise of an eager, obstinate, and unscrupulous science. Courageous, the curiosity of science rifles through the entrails of the earth; voracious, science is that which experiments with the strangest, the most powerful, and the most irregular phenomena; bold, it is what manages to imagine “metaphysical experiments” on the living—animals, “man-apes,” savages, children, criminals, the brain of a living man, and so on—in order to break natural boundaries thanks to new and “useful” discoveries, useful to humankind and to society; disturbed and devouring, science again is what tries to appropriate (until the times that have past and those that will come).  There is an extreme effort for science to surpass itself, with a view to the (perhaps impossible) reconstitution of a genetic totality capable of correcting the “disorder” of the human condition. 
34 These are avatars of curiosity, which is itself an effect of the “disorganization” of nature, and a force for improving it at the risk of devastating it! Blumenberg then gives the floor to Kant, who sees in this hypertrophy of desire for knowledge the root of all extreme intellectual phenomena. He will call Aufklärung not their affirmation, but rather, their negation.
35 The philosophy of the Enlightenment is thus revealed to be quite complex: it is implicated in its own conceptual difficulties at the same time that it is confronted with the crisis of its values. The discovery of the progress of reason, which allows celebrating the primacy of the “philosophical century,” thus also leads to thinking about, beginning even from the excesses of science, a new form of skepsis that is less devoted to the idea of a truth to attain than to the meaning of the pretension to truth.
36 Blumenberg then gives the floor to Reimarus: it is not truth that constitutes the values of humankind, but the sincere efforts made to reach it. Moreover, humankind is not made for truth, but for happiness. He also gives the floor to Rousseau: “But are we therefore made for dying attached to the sides of the well where truth has withdrawn?” The depth of the Democritean well protects us from the rational search for the true, the false veiling of itself with a thousand masks, the true always withdrawing from the eyes of man. And yet Rousseau does not choose the dark. Nor does he renounce a theory of knowledge. He writes it, rather, in a new system of anthropology, while complicating it with new modalities. In place of the inner mirror, he substitutes the story; in place of intellectual intuition, narration; in place of the presence of truth, the experience of the other and the awareness of oneself. In his text on the legibility of the world, Blumenberg cites the Confessions to indicate the subsequent “overcomings” of metaphor, by introducing Rousseau before the divine judges (“the book of his life in hand”). The truth of the book is the truth of his life: “Thus have I acted; these were my thoughts; such was I.” Truth is not the reason, but the knowledge of self: it is the solidest certainty, the only certainty adequate to divine knowledge. Blumenberg finally gives the floor to Lessing: enlightenment is not communicated through an irruption in history, but is acquired through an individual and sincere effort toward truth, that only an “education of humankind” can encourage through personal and individual pedagogical processes. The route toward Romanticism is already open.
37 The interpretation that Blumenberg offers of the philosophy of the Enlightenment cannot, therefore, be summarized in a simple formula. While Blumenberg valorizes the authentic forces and the real conquests of modernity, he in no way intends to be the cantor of a holistic rationalism or the theorist of the unfailing progress of reason. Aware of the horrors and disappointments of contemporary history, and sensitive to the calculation of risks involved in western civilization, he also reads, in the difficult and the precarious relation between history and reason, the gaps and the failures of the Enlightenment in its highest aspirations and noblest intentions.
38 Is this then science's point of no return, arriving at results as tremendous as they are dangerous, in an increasingly pointed rivalry between technology and nature? Is this the twilight of reason, guilty of trying to create the superman? Or, as he is keen on asserting, is this the “distinction between sacrilege and the sober pondering of opportunities and risks”? Blumenberg makes the response from Hans Jonas his own, by appealing to the “principle of responsibility” (Prinzip Veranwortung) under the sign of the anti-utopia. ?The critique of reason is therefore neither an abdication before reason nor a condemnation of its gains: it still remains a critique by reason of its principles, concepts, and discourses, as well as by reason of its limits. 
In his monumental work Die Legitimität des Neuzeit (Frankfurt-am-Main, Germany: Suhrkamp, 1988) (La Légitimité des Temps modernes, trans. Marc Sagnol, Jean-Louis Schlegel, and D. Trierweiler, with the collaboration of M. Dautrey [Paris: Gallimard, 1999]), Blumenberg asserts the legitimacy of modern times as an era made possible by the ruin of the theology of divine omnipotence and the neutralization of the eschatological promise of gnosis. It is a “new” era in the self-positing of its values, and “consistent” in its conceptual devices and expressive figures—and not by derivation from a disguised Antiquity or as a by-product from a secularized theology. Despite the deep divides that characterize it, it is an “original” era and solid in its cultural processes thanks to a “rational authenticity” that it claims.
R Bodei, “Navigatio vitae. Métaphore et concept dans l’œuvre de Hans Blumenberg,” Archives de Philosophie (2004): 214.
Hans Blumenberg, “Licht als Metaphor der Wahrheit,” Studium Generale X (1957): 432–47 (French trans. reviewed and expanded: “La Lumière comme métaphore de la vérité” in Lumières, ed. M. Bouchier [Paris: Éd. Ousia, 2002], 201–30).
Hans Blumenberg Die Lesbarkeit der Welt, (Frankfurt-am-Main: Suhrkamp, 1979) (La Lisibilité du monde, trans. Pierre Rusch and Denis Trierweller [Paris: Le Cerf, 2007]).
Hans Blumenberg, Schiffbruch mit Zuschauer (Frankfurt-am-Main: Suhrkamp Verlag, 1979) (Naufrage avec spectateur: Paradigmes d’une métaphore de l’existence, trans. L. Cassagneu [Paris: L’Arche, 1994]).
Hans Blumenberg, Lebenszeit und Weltzeit (Frankfurt-am-Main: Suhrkamp Verlag, 1988), 146.
Hans Blumenberg, Höhlenausgänge (Frankfurt-am-Main: Suhrkamp Verlag, 1989).
On these debates, see: R. Brague, “La Galaxie Blumenberg,” Le Débat (1995): 173–86; A. Borsari, ed., Mito, metafora, modernità (Bologna: Il Mulino, 1999); J.-C. Monod, Hans Blumenberg (Paris: Belin, 2007); and M. Foessel et al., Modernité et sécularisation: Hans Blumenberg, Karl Löwith, Carl Schmitt, Leo Strauss (Paris: CNRS Éditions, 2007).
O. Agar, “La Légitimité des ‘avant-dernières choses,’” Archives de Philosophie (2004): 239.
In the first part of his book Die Legitimität des Neuzeit, Blumenberg defends his theory—in particular against Carl Schmitt's “secularization theorem.” Through these veiled objections, Blumenberg also responds to the hermeneutics of “hidden meaning” that Hans-Georg Gadamer claimed assigned a “legitimate interpretive function” to the concept of secularization. He replies to Karl Löwith, theorist of a modernity as a secularity-of-Christianity with devastating effects, accusing him “of transforming progress into destiny.” Through an open discussion with Odo Marquard, he refutes his thesis of a structural and thematic identity between theodicy and the philosophy of history, to which he opposes the claim of a constructive role of human liberty. Through a reversal of terms, he finally takes a position against the assimilation between modernity and Gnosticism supported by Eric Voegelin, challenging him with his theory of modernity as a “second overcoming of gnosis.” (cf. I, 20–138 passim [French trans., 20–136]). Here and in what follows, the references to the pages from the French translation are put in parentheses.
Ernst Cassirer, Die Philosophie der Aufklärung (Tübingen, Germany: Mohr, 1932), (French trans., La Philosophie des Lumières [Paris: Fayard, 1966]).
Blumenberg asserts this in his text Die Legimität des Neuzeit, I, 6, 83–86 (French trans., 82–86), in which he is opposed to the theory of the absolute philosophical beginning of modern times: the Cartesian cogito because it is “insufficiently radical,” is in no way insuperable, but can constantly be integrated into other philosophies.
Blumenberg refers here explicitly to the work of Kuhn, The Copernican Revolution (Cambridge, MA: Harvard University Press, 1957) (French trans. La Révolution copernicienne [Paris: Fayard, 1973]), while critiquing his theory of the discontinuity of epochs and the “last word” of science (Die Genesis der kopernikanischen Welt (Frankfurt-am-Main, Germany: Suhrkamp Verlag, 1975), 455 and 596).
Blumenberg, Die Legitimität des Neuzeit, III, 263–530 (French trans., 257–516). To the theme of theoretical curiosity, Blumenberg dedicated the volume Der Prozess der theoretischen Neugierde, (Frankfurt-am-Main, Germany: Suhrkamp Verlag, 1973) (a reworked version of the third part of Die Legitimät).
Hans Blumenberg, Paradigmen zu einer Metaphorologie (Frankfurt-am-Main, Germany: Suhrkamp Verlag, 1960), 142 (French trans., Paradigmes pour une métaphorologie [Paris: Vrin, 2006], 167).
Blumenberg, Die Genesis der kopernikanischen Welt, 234.
Blumenberg, Die Genesis der kopernikanischen Welt, 525–617.
Blumenberg, Die Legitimität des Neuzeit, III, 504–6 (French trans., 493–94).
Blumenberg, Höhlenausgänge, 385.
Blumenberg, Höhlenausgänge, 385–88.
F. Markovits, “Histoire de la raison: périodicité ou périodisation?” in Systématique et iconographie du temps. Essais sur la notion de période, trans. M. Groult (Saint-Étienne, France: L’Université de Saint-Étienne, 2004), 103–25.
This passage from the Notebook of Voltaire (Besterman, II, 573) is cited by Blumenberg, Lebenszeit und Weltzeit, 206.
Voltaire, Micromégas, chap. III. Cited by Blumenberg in Die Legitimität des Neuzeit, III, 474 (French trans., 465).
Voltaire, L’A B C ou Dialogue curieux entre A B C. Quatrième entretien de la Loi Naturelle et de la Curiosité. Cited by Blumenberg in Schiffbruch mit Zuschauer, III, 71.
Voltaire, Dictionnaire philosophique, art. “Curiosité.” Cited by Blumenberg, Schiffbruch mit Zuschauer, III, 71.
Blumenberg, “La Lumière comme métaphore de la vérité,” 228.
D’Alembert, Essai sur les Éléments de Philosophie, IV. Cited by Blumenberg, “La Lumière comme métaphore de la vérité,” 218.
Blumenberg, “La Lumière comme métaphore de la vérité,” 228–29.
Blumenberg, Höhlenausgänge, 396.
D’Alembert to Voltaire, July 31, 1762. The letter is cited by Blumenberg in Höhlenausgänge, 396.
Blumenberg, Die Lesbarkeit der Welt, 159.
Encyclopédie, art. “Encyclopédie,” V, 628. Cited by Blumenberg in Die Lesbarkeit der Welt, 154–59.
Blumenberg, Die Legitimität des Neuzeit, 476–84 (French trans., 467–74).
Maupertuis, Vénus physique, in Œuvres (Lyon, France: J. M. Bruyset, 1768), II: “Darkness is the same, over the future and over the past.” Cited by Blumenberg in Die Legitimität des Neuzeit, III, 486 (French trans., 477).
Maupertuis, Essai de Cosmologie, in Œuvres, I. Cited by Blumenberg in Die Legitimität des Neuzeit, III, 486 (French trans., 477).
Blumenberg, Die Legitimität des Neuzeit, III, 398 ff (French trans., 394 ff).
J.-C. Monod speaks of a “thought of sober emancipation” (La Querelle de la sécularisation. De Hegel à Blumenberg [Paris: Vrin, 2002], 278).