Radical and Moderate Enlightenment? The Case of Diderot and Kant

: I propose the hypothesis that, just as Hume woke him from his dogmatic slumber, and Rousseau revealed the universe of morality to him, Diderot left his mark on the political philosophy of Kant (as George Cavallar and Sankar Muthu note) upon detecting the coincidences between the two authors regarding their cosmopolitanism and anti-i.mperialism. Here, I begin with the distinction between a radical Enlightenment and a moderate Enlightenment, in order to show that in Kant both tendencies could have coexisted; which would explain the different readings of his thought, as is borne witness to by Heine ’ s famous parable or Kant ’ s continual dialogue with Spinoza. Despite having very different styles, the Kant of the 1790s could have been strongly influenced by the anonymous Diderot of the Encyclopédie or the History of the Two Indies. It seems quite clear that the critique of colonialism of Diderot-Raynal could have had a notable influence on the Kant of that decade — he of Theory and Praxis , Perpetual Peace , The Conflict of the Faculties and the Doctrine of Right (that is, the second part of the Metaphysics of Morals ). Die


TwoE nlightenments?
Authors such as Philipp Blom and Jonathan Israel note thato ne should distinguish two Enlightenment traditions, one moderate and another much more radical. This thesis has been presented in two relatively recent books, both from 2010.Iam referring to AWicked Company: TheF orgotten Radicalism of the European Enlightenment and ARevolution of the Mind: Radical Enlightenmentand the IntellectualO rigins of Modern Democracy (byB lom and Israel respectively).
Accordingt oB lom, Kant and Voltairea re the representatives of am oderate Enlightenment (reformista nd deist), while the Encyclopedists, led by Diderot and D'Holbach, werec ommitted to am aterialist and revolutionary worldview that encouraged an enjoyment of living and promotedthe right to live with dignity and in freedom,ont he basis of ad eeplyi mmanentist philosophy. Thiss econd current wasinspired by the Western tradition of freethinking, which extends from Epicurusand Lucretius up through Spinoza and Bayle, usesscepticism as a philosophical method and takes the analysis of the passions as the best guide for the understanding of human affairs.
Jonathan Israel further emphasizes that Bayle and Spinoza inspired the most radical ideas of the Encyclopedists, highlightingt he fact thatR obespierre and the Jacobins viewed the philosophes as being courtesans of absolutism, and instead glorified Rousseaua nd Voltaire, buried in the Pantheon as champions of the French Revolution. However,I sraeln otes that in reality,the changei nm entality had been achieved by the Diderot of the Encyclopédie,togetherwith other works that had ahugemedia impact on that era. Thiswas especiallythe case for the Philosophical and Political Historyo fE uropean Settlements and Commerce in the TwoIndies-atrue engine of war against the structures of the Ancien Régime, particularlyinthe last section of the work, whereits texts are both quantitatively and qualitativelys ignificant.
Accordingt ot he readings thatB lom and Israel propose, these twoc ontrary Enlightenment traditions had very little to do with one another,with the more radical current having impeded the success of the more moderate path. Nevertheless, although Is ympathize greatlyw ith their historiographical strategy, and even more with the effort to highlight the radical nature of the Enlightenment project in its totality,i ts eems to me that this emphasis should not overshadow the role playedbypresumablymore moderate thinkers.Wemust redeem Diderot,who is without doubt the thinker that is the most contemporary to us among the philosophers of his age (Diderot 2009,p.13-48)-but this should not mean forgetting about the decisive influencee xercised on our chaotic times by such important authors as Rousseaua nd Kant. As aresult,itwillbeofinterest to comparethe possibleconfluences of these two contrary Enlightenmentt raditions and ask ourselves, for example, whether two of their most outstanding representatives, i. e. Kant and Diderot,a re in fact completelyantagonistic thinkers,aswould be suggested by the strict distinction between the moderate and the radical currents of the Enlightenment;oristhere, as Iv enture to suggest in this inquiry into the possible traces left by Diderot's thoughtinKantian philosophy, some familyresemblancethatreveals acommon ancestry?
Indeed, the intellectual circle close to Kant included Raynal, especially thanks to the presenceo ft he abbé at the court of Frederick II (Barcarel 2011, p. 91). Kant himself cited the German translation of the Historyofthe TwoIndies in one of the editions of his Physical Geography (Kant 1816,p.223:AA26.1: 280), commentingont he Dutch East Indies Company, which he criticized so much in Perpetual Peace. Reconstructing Kant'saccess to the work of Diderot-Raynal is a tremendouslya rduous task-one alreadyb egun in Jean Ferrari'sw ork Les sources françaises de la philosophie de Kant (Ferrari 1979). Simone Goyard-Fabrecalls it am ysterious path, and suggests that the researcher will need the investigative skills of ad etective duet othe very few precedents we have (Goyard-Fabre1996, p. 127;Quintili 2009,p .7 5-89).

Spinoza inside both Enlightenmentt raditions
Just as manya uthorso ft he radical Enlightenment did, Kant maintained ac ontinual dialog with Spinoza (De Flaviis 1986), beginning with his pre-critical writingsa nd continuingt hrough the Opus postumum,a nd featuring in his Lectures and in the Reflections he noted down for himself. Spinoza, the alma mater of the radical Enlightenment,r emained for Kant the example of the virtuous atheist, the possibilityo fw hose existenceP ierre Bayle had upheld, as we read in the 87th paragraph of the third Critique-ap aragraph added to its second edition (KU, AA 05,p .4 27). On manyo ccasions,K ant described Spinoza as someone of ag ood heart who behaveda sareligious man would do;a na theist who acted morallyd espite not believing that anys uperior being would rewardh is good behaviourw ith the gifto ft he supreme good.
On the other hand,t hat substrate of nature that goes beyond the sensible, and which would be common to mechanism and teleologism, that Something (Etwas, with the capital letter;K U, AA 05,p.466) that Kant referredtointhe Cri-tique of Judgment,would relax Kant'sf amousd ualism and bring him closer to the monism of Spinoza (KU, AA 05,p p. 392-393). Indeed, he would recreate the latter'sfamous Deus sive Natura when, in the Opus posthumum,heidentifies God with self-legislatinge thical-practical reason (OP, AA 21,p .1 45), since the moral lawr esides within us and merits worship comparable to that historically rendered to divinity.
One of the sources through which Kant had accesstoSpinoza mayhavebeen the article on Spinozism in the Encyclopédie,whereDiderot ascribes his own materialism to modernSpinozism (which should not be confused with the older variety,since for the modern thinker there is nothing but matter). Beginninginhis first work, TheSkeptic'sW alk,Diderot uses Spinozism to mediate between deists and atheists (Diderot 2016,p .1 15). The deist reproaches the atheist for leaving everything in the hands of chance; the atheistresponds that one cannot describe the author of an infinite compositewhose beginnings, current and final state are unknown; and the Spinozist seeks the origin of the universe within himself, via a careful studyofthe place that we occupy in it,just as Kant would do with moral law. One might also ask whether Spinoza's Ethics, Demonstrated in Geometrical Order isn'tone of the reasons that Kant wrotepart of the Analytics of his Critique of Practical Reason in am athematical style, employing definitions, theorems, scholia,p roblems,d emonstrations and postulates (Aramayo 2013a, p. 22), even when they led to at hesis completelyo pposed to that of Spinoza'se ssay.
Spinoza does not seem to servewell as acriterion for distinguishingthe radical Enlightenment thinkers from the moderates,g iven that both Diderot and Kant share an admiration for and interest in him, as has been the casef or a good portion of modern thinkers. In some way, the case of Spinoza bears witness-as Is tated earlier in regard to Raynal-to the fact that the walls between the representatives of both tendencies of the Enlightenmentproject are quite porous.I twould thus be wrong to treat the thought of the thinkers on each side as residingi ns ealed or even contradictory compartments.

Heine'st estimony
Of course, it would be difficult to make Kant fit entirelyw ithin the limits of the moderate Enlightenment if one accepts how Heine describes him in On the Historyo fR eligion and Philosophyi nG ermany. The passagei nq uestion is wellknown, thanks to its extraordinary rhetorical appeal. Heine tells the French that they are much more prudish than the Germans. After taking the Bastille, the onlything the French managed to do was kill aking,who had in fact already lost his head long before he had been decapitated. In reality,H eine continues, one does too much honour to Robespierre when one compares him to Kant.Robespierre could lose his temper in bloodyf ashion, but when it came to the Supreme Being,h ew ashed his bloodyh ands and put on his Sundayc lothes. In contrast,the ruthless Kant wasable to stormthe heavens, annihilatingtheir entire garrison and even the soldiers of their ontological, cosmological and psychotheological corps. God himself, now lacking even ademonstration of his own existence, has succumbed, and thereisn ol onger anydivine mercy, nor aF ather's goodness, nor even anyf uturer ecompense for present-day privations.T he immortality of the soul is on its death bed. One hears nothing but moans and death rattles. In the face of this spectacle, the faithful servant Lampe becomes frightened and breaks out in tears.S oK ant has pity on him and shows that he is not merelyagreat philosopher,b ut also ag ood man, using the magic wand of the practical reason to resuscitate the God thath ad been condemned by theoretical reason. It is very possible, adds Heine, thatK ant undertook that resurrection not onlyb ecause of compassion for Lampe,b ut alsob ecause he feared the police.
To finish off his clevera nd instructive piece of satire, Heine noted another subtle parallelism. Just as some had claimed that Robespierrew as an agent of the Britishprimeminister, therewerealsothosewho, in atotallyconfused manner,thought that Kant had made as ecret pact with his adversaries, and that he had destroyed all the philosophicalproofs of the existenceofGod in order to let the world know that one could never arrive at knowledge of God via one'sr eason, so as to implythat we should instead relyonrevealedtruth. This is the point of Heine'ss tory that Iw ishedt or ecall.

Familyr esemblanceb etween Diderot and Kant
My hypothesis is that,while it might be very difficult to prove, it would not be strangeifthe influenceofDiderot on Kant weresimilar to that of Rousseau(Aramayo 2015a, p. 53;2 005,p .2 37-252; 2006,p .1 7 -54;2 016,p .1 1 -60;c f. 2017, p. 123 -135), which Kant himself recognizes, and which is easy to trace in his texts,asIm yself have emphasized on various occasions. Indeed, Ihavebecome ever more convincedthatifthe scepticism of Hume was able to wake Kant from his dogmatic slumber (Prol, AA 04,p.260) and Rousseauopened the moral universe to him (HN AA 20,p.44; cf. Aramayo,2013b, p. 16 -36), Diderot might have been the one who openedh is eyes to the world of politics,through certain articles in the Encyclopédie and his anonymous contributions to the Historyo ft he TwoIndies. In this view,Diderot mayhavehad agreat influenceonK ant'spolitical and even legal reflections-despite the fatc that Kant did not citeh im, be-cause he did not know of his role in the authorship of these two collective works (which we nevertheless know that Kant read).
Recentlym orea ttention has been paid to the paradoxical intensity of this indirect relationship. GeorgCavallar,inarecent book about Kantian cosmopolitanism, relates that he was very surprised to discover that,inregards to hospitality and cosmopolitanism, Diderot was so close to Kant,despite the fact that "his publications did not form part of [Kant's] library,a nd it is not clear that he influenced him" (Cavallar 2015,p .60).
It was certainlyn ot unusual that Kant lacked ac opy of the Encyclopédie in his personal library, givenh ow much it cost,but it would have been highlyu nlikelyt hat he did not have access to it via the library of his university.The presence of the preliminary discourse attributed to D'Alembert,n oted at the beginning,o ffers proof of the attention dedicated to this immense collective work. It is worth bearing in mind that as earlyas1759, Kant had recommended to his students and correspondents (such as Herder and Hamann)t hatt hey read Diderot and the articles he wrotefor the Encyclopédie-although he certainlylacked any knowledge of his authorship-and even proposed that Hamann translate some of them (cf. the letter of GeorgHamanntoKant of July 27,1759, Br,AA10, p. 9). This exchangeofletters indirectlytells us that Kant knew the first volumes of the Encyclopédie and might have had access to such articles written by Diderot as "Political Authority", "Citizen", "Eclecticism", "Encyclopédie" and "Philosopher"and it is equallylikelyt hat he paid attention to the later volumes thatappeared up through 1765.
Let us takealook at these lines of the article "Eclecticism": The eclectic is aphilosopher who, treadingonprejudice,tradition, authority,inaword, everythingt hat subjugates the masses, dares to think for himself,tot race things back to the clearest general principles,examine them, discuss them, to admit nothing except what the testimony of his experience and his reason tells him;and on the basis of all the philosophies that he has analysedwithout partiality creates aphilosophythat is his own. He is not at all am an whop lants or sows, but rather one whog athers and winnows [italics RRA].
This text is laterechoed by Kant,beginning with that 'winnowing' thatmust subject everythingtothe sieveand strainerofreason itself (albeit without forgetting experience)a nd puttinga side the prejudices that arguments from authority invariablyinvolve, since everything must be subjected to critique and to the tribunal of reason. Diderot and Kant explicitlyshare one of the principal goals of the Enlightenment program. This daring to rely on one'sown understanding,which Kant identifies as the banner of the Enlightenment,corresponds closelyt othe 'dar[ing] to think for yourself' thatDiderot had formulated some years previouslyinhis En-cyclopédie article. Both Kant and Diderot want to free the human being from all moral or political tutelage and to advocate an Enlightenment thata llows us to leave behind our 'guilty minorityofa ge',tou se the Kantian expression. Diderot envisages the Encyclopédie as having this same objective:i ts mission is to changet he common wayo ft hinking, promotingt hinking for one'ss elf thanks to those cross references thatpermiteach reader to extract his own conclusions, by combiningdifferent perspectivesonasingle problem (Aramayo 2012,p.357-385;2015b, p. 319 -338). In What is the Enlightenment?-atext from 1784,the year in which Diderot died-Kant advocates an 'authentic reform in our wayofthinking' that would annihilate prejudices.The dynamic of the public use of reason, together with the Kantian consciousness of the pragmatic reality of our human condition, could well reflect an attempt to compose something analogous to what Diderot designed with the great project of the Encyclopédie.
In Pro and Contra,D iderot holds that "posterity is for the philosopher what the other world is for the religious man"-something that,a sIh avem aintained elsewhere, Kant would subscribe to with his philosophyo fh istory,w heret he postulate of the immortalityoft he soul is translatedtothatasymptotic meeting of the species with its destinyt hat marks the handover to the new generation (Aramayo 1992, p. 114-115). Similarly,the end of the Idea for aUniversalHistory with aCosmopolitan Purpose proposes a 'philosophicalhistory' with aclearlypolitical purpose, i. e. the channelling of the ambition of the heads of State and their servants towardst he onlymeans that can enable them to 'conquer aglorious memory in posterity' (WA, AA 08. p. 31). Here Kant is speakingv ery likeDiderot,who speaks of monuments carved in the memoriesofmen, consecratedto the champions of freedom and technical inventions, who he personifies at one point in the figures of Las Casas and Benjamin Franklin respectively (Skrzypeck 1995,p .79-88).
Another setoftraits that might reveal afamily resemblance between Diderot and Kant are the esoteric and exoteric aspects of our two authors. After the traumatic experience of being imprisoned at Vincennes,D iderot decided to fool the censors with the cross references of the Encyclopédie and his anonymous pages in the Historyo ft he TwoI ndies,a bandoningh is novels and other writingsi na drawer,h oping thatt hey might be enjoyed by posterity.K ant alsou sed ad ifferent style in his classes (in which, apart from his most lay-oriented courses,h e was obligatedt of ollow at extbook)t hanh ed id in his published writings and in the Reflections thathewrotestrictlyfor himself. It is as though he had wanted his Nachlass to find another kind of readership with the passageoftime-something very much in agreement with his distinction between ap ublicu se of reason (intended for an educated universe of readers) and ap rivateu se in the exercise of at rusted function (WA, AA 08, p. 37).

Cosmopolitanism,a nticolonialism ¹ and the Rightso fM an
Whatever the casemay be, there is at least one author who has clearlyhighlighted the Kantian debt to aD iderot immersed in political intervention. Sankar Muthu, in his book Enlightenmenta gainst Empire,a rgues that Diderot'sr adical political and historical writingsa ppeart oh aveh ad an influenceo nK ant,a nd goes so far as to holdt hat "in many regards Kant represents the spirit,a nd on occasion the letter,o fD iderot'sa nti-imperialism" (Muthu 2003,p .1 23)-so much so that certain aspects of his political philosophyc an be said to be cut from the same cloth. GeorgCavallar,despite not providing anyconclusive proofs, also emphasizes the analytic coincidences between the idea of cosmopolitanism in Kant and in Diderot (Cavallar 2015,p.60-63). Forthe latter also distinguishes, in his contribution to the Historyofthe TwoIndies,between aright of necessity,a right of visitation, ar ight to be ag uest and ar ight to establish oneself in at erritory,makingthe right of visitation aperfect right in the case that the traveller's life is in danger.Incontrast,the right to be the guest of aforeigner would be imperfect and contingent,a nd would onlyb ea ctivated if there was an agreement between the two parties. This is aclassification very close to what Kant provides in Perpetual Peace,wherehedistances himself substantiallyfrom the principles of traditionali nternational law, which tended much more stronglyt ol egitimate the right of European peoples to settle in the New World.
Another point at which Diderot and Kant fullycoincide is their clear anticolonialism (Benot 1970), which in the case of the latter reallybegan to flower beginning in the second half of the 1790s.F urthermore, what Pauline Kleingeld has called Kant'ss econd thoughts on colonialism-and, al ittle earlier, Kant'ss econd thoughts on race (Kleingeld 2007,p.573 -592;2014,p.43-67)-which she sees as as omewhat capricious changeina pproach on his part,could have been due to his readingo ft he Diderot-Raynal work.
Of course, the symmetry of their approachesm ust be viewed through the prism of two different styles that respond to equallydiverse personalities and circumstances. This occurs when Kant,inhis Doctrine of Right,rejects as reprehensible the colonization of new lands thathad been previouslyoccupied by forceor by fraudulent purchase, making use of European superiority,and withouttaking into account their prior possession, in order to give the savage peoples al egal  Foramoreextensive treatment of what Ihavenotedhere, Ireferthe reader to my forthcoming work coauthored with Nuria Sánchez Madrid. status, something that would validatethe use of anydishonourable means whatsoever,and which he judgest obeacloak for injustice, or 'Jesuitism' (MS,A06,p. 266). Forhis part,the Diderot of the Supplementrefers to Jesuitism with avery different style, offering this description of the Jesuits in Paraguay: Those cruel Spartans in black habits behavedwith their Indian slaveslike the Lacedaemonians with their helots: they condemned them to continual work, they gave them no right to property,t hey kept them brutish and tied down with superstition, they demanded deep veneration fromt hem, walked among them with aw hipi nh and and lashed every age and sex without distinction. ( Supplement,OC II:,p. 542) The critique that Kant directed at colonialist practices at the end of his life parallels in good measure the demand that should be made of the traders, missionaries and emissaries of European powers, i. e. thatt hey behave in ar espectful waytowardsthe lawthat should rule over their contacts with the so-called 'savages'.InDiderot'sview, European nations should judge their behaviour by placing themselvesi nt he place of the other.J ust as Kant does, he criticizes the fact that when European voyagers come to ar egion of the New World that is not occupied by anyp eople of the Old World, they immediatelyd ecidet hat thatl and belongst ot hem.
What would they think if some savages, upon landing upon their coasts,did something similar?How can they claim anyright at all over men who are similar to them, or over the products of theirl ands?
Forisn'tthe natureofproperty the same in every land, based on takingpossession through work, and on al ong and pacific enjoyment? Europeans,c an yout ell me at what distance from your residence this sacred title becomes invalidated?Attwenty paces?Atten leagues? Yousay not.Well then, neither does it lose effect at ten thousand leagues.(Of the Colonies in General,OCI II, p. 697) Subscribing avant-la-lettre to one of the pillars of Kantian cosmopolitan law, Diderot speakst ou so ft he 'hospitality' that voyagers have had the occasion to enjoy,for instance in Brazil. He alsocoincides with Kant in holding thatthe spirit of commerce is aguarantee of peace, since awar between nations of traders is like adevastatingfire, when bankruptcies become aquestion of State. Although Kant is not as explicit in his theses concerning non-European cultures,iti sperhaps preciselyfor that reason that his reflections have adeeper theoretical basis and have been as much or more fecund than thoseput forth by Diderot.Without doubt,the Kantian approach pays more attention to the legal difficulties that the European powers encountered in justifying their occupation and annexation of territories on other continents,which leads him to emphasize the rights acquired over their territories by peoples without States.AsK.Flikschuh has emphasized, what is most characteristic of Kant'slegal cosmopolitanism is his attention to the form, i. e. to the mere formality of the contact that should take place between different peoples, independentlyo ft heir degreeo fc ivil maturity.
Afinal coincidencethat Iwould like to emphasize, in this inquiry into apossible familyresemblance between the political philosophies of Diderot and Kant, is the enthusiasm they had for the American and French revolutions. In afamous note to paragraph 65 of the Critique of Judgment,K ant refers to the French Revolution as an example of the transformation of apolitical bodyinto atrue organism (although we do not have anyevidence of anysimilar reactions to the American Revolution). Diderot,who could not opine on the French Revolution, since he had died five years prior,d id comment on the Americano ne, which in his judgment could provide: … all the inhabitants of Europe with ar efugea gainst fanaticism and tyranny, and instruct those whog overn men on the legitimateu se of authority,a iding in the prevention of an extremelyunequal distributionofwealth and the corruption of morals. (Essay on the Reigns of Claudius and Nero,OCI ,p .1197) Forhis part,asiswell known, the Kant of the Conflict of the Faculties makes the French Revolution into al andmark of the moral progress of humanity;a nd he goes on in even more depth in Reflection 8077,b ut Iw ill refrain from going into greater detail regardingt hese well-known texts.

Conclusion
In my view,the Kant of the 1790s,i.e.the author of Theoryand Practice, Perpetual Peace, TheM etaphysics of Morals and TheC onflict of the Faculties,becomes more intelligible if we postulate thatheknew (though in what was surelyanunconscious manner)the battle writingsofDiderot-thosetwo intellectual engines of wart hat are the Encyclopédie and the Historyo ft he TwoI ndies.
Iw ould like to sayt hat Kant read Diderot,without knowing he did so, and that the latter revealedt oh im the global condition of politics, just as Rousseau had done for him regardingthe moral universe. Thus, Ibelievethatitisplausible to claim thatD iderot had an impact on the political thoughtofK ant. "Forcem e to be silent about religion and government,and Iwill have nothing else to say", says Diderot in TheS keptic'sW alk,a nd it is preciselyt ot hese twot opics-the throne and the altar-thatK ant dedicates his writingso ft he 1790s,p robably under the unknown influenceo fD iderot.