Diderot: The Encyclopedian of the Enlightenment and the Martyrdom of Evil

"On the other hand, I came across Diderot yesterday, who delighted me and moved my innermost thoughts. Almost every dictum is a spark of light that illuminates the secrets of art, and his remarks are so much from the highest and innermost of art that they also dominate everything that is only related to it and are just as much pointers for the poet as for the painter. If the writing does not belong to you yourself, that I can keep it longer and get it again, then I will prescribe it to myself

Just such a strange example is given by Diderot, who, with such a high genius, with such deep feeling and clear understanding, could not come to the point of seeing: that culture must go its own way through art, that it cannot be subordinated to any other, that it connects so comfortably with all the rest, etc., which would be so easy to understand, because the fact is so clearly evident."

Schiller to Goethe, Jena, December 12, 1796.

"Among the French, Diderot in particular insisted in this sense on naturalness and imitation of the existing."

Hegel, Lectures on Aesthetics

Denis Diderot was a central philosopher of the Enlightenment era who left a mark on the fields of philosophy, literature, and social thought in the Empirical tradition. Born in 1713 in Langres, France, Diderot's intellectual path was shaped by a diverse range of influences, but primarily the popular Materialist thinkers that were dominating France. He wrote novels, plays, stories, essays, dialogues, art criticism, literary criticisms and translations largely in dialogic form. He published at the same time as Adam Smith, Immanuel Kant, Rousseau and Voltaire. He drew inspiration from the Empiricist works of John Locke, Pierre Bayle, and David Hume. Diderot's own philosophy centered on the belief in human reason, the pursuit of knowledge, and the importance of freedom in society. His materialistic perspective, which emphasized the primacy of matter and the rejection of metaphysics writ large, laid the foundation for later materialist thinkers such as Karl Marx, although Marx did not think much of Diderot as he did of Bayle and Feuerbach.

Diderot was a friend of Rousseau until their falling out, a personal art critic of Catherine II, Empress of Russia, and rubbed shoulders with the giants of his day, but did not gain recognition in his lifetime. Unknown to most of his major contemporaries, distanced from the polemics of his day, and badly received by the Revolution, Diderot had to wait until the end of the nineteenth century to receive the interest and recognition of posterity in which he had placed some of his hopes. Some of his texts remained unpublished until the 21st century, and the modern edition of his complete works, begun in 1975 by the Parisian publisher Hermann, has not yet been completed. Still, he contributed to some of the greatest works of history, including Rousseau’s Social Contract.

One of Diderot's most famous contribution to history is as his role as the chief editor of the Encyclopédie, a monumental project that sought to compile and disseminate knowledge across various disciplines. He is often referred to as “the Encyclopedia”. This ambitious undertaking was massive effort involving numerous contributors, and it aimed to challenge traditional authority and promote the ideals of the Enlightenment. Diderot's vision for the Encyclopédie was to create a compendium that would empower individuals to think critically and independently, fostering intellectual progress in society, similar to Voltaire’s Philosophic Dictionary. It is a prime example of an Enlightenment text.

Diderot did not seek a coherent philosophical system like many others of his day apart from his Encyclopedia, but he did believe in the unity of all knowledge. In most of his philosophic works, he brings ideas together and contrasts them, which is reminiscent of Nietzsche’s works. Diderot also frequently reworked his texts, and in the second half of his life even wrote a few additions (notably to the Philosophical Reflections and the Letter on the Aveugles) to reflect his own evolving thinking. Most of his works are intended to stimulate thought rather than to express his personal ideas, although he does posit fundamental metaphysical truths. Reason is Teleological in nature, and his materialism has elements of an Eschatology. In the introductions of his massive Encyclopedia, he posits a unity of knowledge which is largely materialistic, but allows room for Theology to be necessary for a healthy society, a perspective it sounds like he adopted from Voltaire:

The physical beings act on the senses. The impressions of these Beings excite the perceptions of them in the Mind. The Understanding deals with its perceptions only in three ways, according to its three main faculties, Memory, Reason, Imagination. Where the Understanding makes a pure and simple enumeration of its perceptions by Memory; where he examines them, compares them, and digests them by Reason; where he likes to imitate them and counterfeit them by the Imagination. Whence results a general distribution of human knowledge which appears fairly well founded; in History , which relates to Memory; in Philosophy, which emanates from Reason; & in Poetry, which is born from Imagination.

The natural progress of the human mind is to rise from individuals to species, from species to genera, from neighboring genera to distant genera, and to form at each step a Science; or at least to add a new branch to some Science already formed: thus the notion of an uncreated, infinite Intelligence, &c. that we encounter in Nature, and that sacred History announces to us; and that of a created intelligence, finite & united to a body that we perceive in man, & that we suppose in the brute, have led us to the notion of a created, finite Intelligence, which would have no body ; & from there, to the general notion of the Spirit. Further the general properties of Beings, both spiritual and corporeal, being existence,, duration , substance , attribute , &c. these properties have been examined, and the Ontology, or Science of Being in general, has been formed from them . So we had in reverse order, first Ontology; then the Science of the Spirit, or Pneumatology , or what is commonly called Particular Metaphysics : & this Science is distributed in Science of God… hence Religion & Theology proper, whence by abuse, Superstition . In the doctrine of good and evil spirits, or of angels and demons; hence Divination , & the chimera of Black Magic . Into Science of the Soul, which has been subdivided into Science of the reasonable Soul which conceives, and into Science of the sensitive Soul, which is limited to sensations.

German Continental Idealism

Kant refutes the presuppositionless science of Diderot and the French Materialists, which were inspired by Kant’s great enemy Hume, across many works including Metaphysical Foundations of Natural Science (Metaphysische Anfangsgründe der Naturwissenschaft). Kant and Hegel focused on their own work and rarely wrote any polemics, but Hegel does comment on Diderot in his later works. In his Lectures on Aesthetics, Hegel comments extensively on Diderot, once again exposing the supposedly non-existent Metaphysical side of Materialism and Natural Philosophy:

What was called French philosophy, Voltaire, Montesquieu, Rousseau, d'Alembert, Diderot, and what then appeared as Enlightenment in Germany, also frowned upon as atheism, we can distinguish three sides of it: 1. its negative side, which was most resented; 2. the positive; 3. the philosophical, metaphysical.

Among the French, Diderot in particular insisted in this sense on naturalness and imitation of the existing. Among us Germans, on the other hand, it was Goethe and Schiller who in a higher sense took a similar path in their youth, but within this lively naturalness and particularity sought deeper content and essential conflicts of interest..

In the similar relation Goethe already says in his notes to the translation of Diderot's Versuch über die Malerei: "One by no means admits that it is easier to make a weak coloring more harmonious than a strong one; but admittedly, if the coloring is strong, if colors appear vivid, then the eye also feels harmony and disharmony much more vividly; but if one needs the colors weakened, some bright, others mixed, others soiled in the picture, then admittedly no one knows whether he sees a harmonious or disharmonious picture; but that one knows at most to say that it is ineffective, that it is insignificant."

Diderot, Lessing, also Goethe and Schiller [Hegel knew Goethe and Schiller personally] in their youth turned in more recent times mainly to the side of real naturalness: Lessing with full education and subtlety of observation, Schiller and Goethe with preference for the immediate liveliness of uncompromised coarseness and power. That people could speak to each other as in the Greek, but mainly and the latter statement is correct in the French comedy and tragedy, was considered unnatural.

Friedrich Nietzsche, a philosopher of the 19th century, also commended Diderot's critical approach, asserting, "Diderot taught us to doubt everything." In his 1881 The Scarlet Dawn, Nietzsche comments:

“Only the lonely man is evil," cried Diderot: and immediately Rousseau felt mortally wounded [Rousseau talks about this dispute in his Confessions]. Consequently he admitted to himself that Diderot was right. In fact, every evil inclination in the midst of society and conviviality has so much compulsion to put on, so much larvae to undertake, so often to lay itself in the Procrustean bed of virtue, that one could quite well speak of a martyrdom of evil. In solitude all this falls away. He who is evil is most so in solitude: also best-and consequently, for the eye of him who sees everywhere only a spectacle, also most beautiful.

Presuppostionless Science and the Protestant Tradition of Self-Deception

Diderot's philosophy emphasized the power of reason and the importance of empirical observation, although he shunned away from clear Atheism. In his early Philosophic Questions, he writes “superstition is more unjust to God than atheism”.  His semi-Atheism is similar to that of Voltaire- he is really just so upset with the religious infighting and violence of the 17th century, that Atheism becomes appealing, but he never gives himself fully over to it. He writes in the same work “Someone was once asked if there were any true atheists. Do you believe," he replied, "that there are any true Christians?”

He did have a love of Empiricism. In his 1749 Letter on the Blind, Diderot contemplated the nature of perception and argued that sensory experience shapes our understanding of reality. He wrote, "We see only what we are able to see. Sight is a perspective sense like touch, taste, and smell." This materialism emerged later in his life, but his emphasis on morality kept him returning to the concept of beauty, which he could not bring himself to say is purely a material, epiphenomenal reality.

The materialist Sociologist Michel Foucault noted, "Diderot reminds us that philosophy should not only address metaphysical questions but also engage with the concrete realities of human existence." Marx could not agree more. The fundamental problem here, as Orwell, Solzhenitsyn and Dostoevsky reply, is that this worldview is itself a religion- the very perception of the material world is metaphysical first, so the Materialist worldview is never what it claims. Freud made this accusation about Marx and the Materialists like Diderot. Freud saw that the French and German Materialist trends were still religious in nature despite their violent claims to be purely materialistic, atheistic and pro-science:

Marx's theory I have been alienated by sentences such as that the development of social forms is a natural-historical process, or that the changes in social stratification emerge from each other on the path of a dialectical process. I am not at all sure that I understand these assertions correctly, nor do they sound "materialist," but rather like a precipitation of that dark Hegelian philosophy through whose school Marx also passed.

This was exactly what Marx accused Feuerbach of, a link in a long chain of Materialists accusing the materialists before them of not being real materialists, mimicking the infinite feuds we see in Protestantism. Jung makes this exact same accusation against Freud's repetition of Feuerbach’s Materialism- Freud's entire worldview rests upon deeply held religious axioms- a Teleology. The act of science itself is a belief, utilizing a set of a priori assumptions that reality can manifest itself to consciousness in a rational fashion. Marx writes in The Holy Family:

We need not speak of Volney, Dupuis, Diderot, etc., as little as of the Physiocrats, after we have proved the double descent of French materialism from the physics of Descartes and from English materialism, as well as the opposition of French materialism to the metaphysics of the seventeenth century, to the metaphysics of Descartes, Spinoza, Malebranche, and Leibniz. This opposition could only become visible to the Germans since they themselves stood in opposition to speculative metaphysics.

Freud argues most clearly against Platonic Ontology in his 1927 Die Zukunft einer Illusion, where he states that science can be ideology or metaphysics-free, i.e. Presuppositionless. Freud accused Marxism of being "darkly Hegelian", but Freud's views on history as having an intrinsic Telos, which he adopted from the metaphysician Darwin, is also deeply Hegelian. His entire Phylogenesis analysis is deeply Teleological. Nietzsche makes this observation about the Metaphysical roots of Darwinian Science, which believed to be "presuppositionless science":

[Hegel] dared to teach that the species concepts develop apart from one another: with which sentence the minds in Europe were performed to the last great scientific movement, to Darwinism for without Hegel, no Darwin….Hegel, in particular, was its retarder par excellence… in his grandiose attempt he made to persuade us to the divinity of existence.

Freud, of course, somehow managed to find incest in Diderot, which he mentions in his Lectures on Psychoanalysis:

Among the writings of the encyclopedist Diderot you will find a famous dialogue Le neveu de Rameau, which was edited in German by no less a person than Goethe. There you can read the curious sentence: Si le petit sauvage était abandonné à lui-même, qu'il conservât toute son imbécillité et qu'il réunît au peu de raison de l'enfant au berceau la violence des passions de l'homme de trente ans, il tordrait le col à son père et coucherait avec sa mère.” [If the little savage were left to himself, if he retained all his imbecility and combined the little reason of the child in the cradle with the violence of the passions of the man of thirty, he would wring his father's neck and sleep with his mother."]… And this is one of the motives why we have placed the study of dreams before that of neurotic symptoms.

Schopenhauer, who coined the basic constructs of the Unconscious used by Freud, found Diderot to be a useful philosopher, but one who collapse the Subject-Object paradigm with this Aristotelean materialism, thus removing the will to live. Nietzsche would develop this line of thought further. Schopenhauer notes:

Diderot already said, in Rameau's nephew, that those who teach a science are not those who understand it and practice it seriously, as they have no time to teach it. Those others live only on science: it is to them an efficient cow that supplies them with butter.

Victor Hugo comments on the French philosophers extensively, mentioning Diderot hundreds of times across his works. In Les Miserables he writes:

The encyclopedists, led by Diderot, the physiocrats, led by Turgot, the philosophers, led by Voltaire, the utopians, led by Rousseau, these are four sacred legions. The immense advance of humanity towards the light is due to them. They are the four avant-gardes of the human race going to the four cardinal points of progress, Diderot towards the beautiful, Turgot towards the useful, Voltaire towards the true, Rousseau towards the just. But, beside and below the philosophers, there were the sophists, poisonous vegetation mixed with salubrious growth, hemlock in the virgin forest. While the executioner burned on the staircase of the palace of justice the great liberating books of the century, writers today forgotten published, with the privilege of the king, one does not know which strangely disorganizing writings, avidly read by the miserable.

Rousseau, Diderot and the French Revolution

Diderot was overshadowed by the personalities of Rousseau and Voltaire. As Victor Hugo said in The Toilers of the Sea:

Is it possible to speak about Voltaire calmly and fairly? When a man dominates a century and embodies progress, he does not have to deal with criticism, but with hatred.

Goethe likewise recognized that Voltaire eclipsed the other French intellectuals of his day:

In Voltaire, the highest writer conceivable among the French, the one most in keeping with the nation. The qualities that are demanded of an intellectual man, that are admired in him, are manifold, and the demands of the French are in this respect, if not greater, yet more manifold than those of other nations. Depth, genius, perception, sublimity, nature, talent, merit, nobility, spirit, beautiful spirit, good spirit, feeling, sensibility, taste, good taste, understanding, correctness, decorum, tone, good tone, court tone, variety, abundance, richness, fruitfulness, warmth, magic, grace, gracefulness, pleasingness, lightness, vivacity, refinement, brilliant, saillantes, petillantes, piquant, delicate, ingenious, style, versification, harmony, purity, correction, elegance, perfection. Of all these qualities and expressions of mind, perhaps only the first and the last, the depth in the layout and the perfection in the execution, can be disputed to Voltairen. All that, by the way, of abilities and skills in a brilliant way fills the breadth of the world, he has possessed and thereby extended his fame over the earth.

Still, Diderot's humanistic ideas found resonance in the realm of political thought and largely coincided with Rousseau and Voltaire.. His advocacy for individual freedom and the importance of reason informed his views on governance and social organization. Diderot's political thought aligned with the ideals of the broader Enlightenment, which emphasized the rights and autonomy of individuals. His work played a significant role in shaping the ideas that would later underpin democratic societies along with Rousseau and his social contract.

Rousseau diatribes about his interactions with Diderot extensively in his 1790 Confessions. The two shared a close intellectual friendship until Rousseau broke it off due to Diderot criticizing his life choices, something Rousseau did to many friends. Eventually he broke with him for telling a secret he told him in confidence. Still, Rousseau hailed Diderot as a champion of freedom, declaring, "He has courageously battled against prejudice, fanaticism, and intolerance." Rousseau’s Discourse on Inequality was one of Diderot’s favorite works, and the two reviewed and improved each other’s works. Rousseau writes in Confessions:

Diderot, younger than them, was about my age. He liked music, he knew the theory of it; we spoke about it together: he also spoke to me about his projects of works. This soon led to a more intimate relationship between us, which lasted fifteen years, and which would probably still last, if unfortunately, and through his fault, I had not been thrown into his same profession [Poetry]….

I loved Diderot tenderly, I esteemed him sincerely, and I counted with complete confidence on the same feelings on his part. But, fed up with his indefatigable obstinacy in eternally antagonizing me about my tastes, my inclinations, my way of life, about everything that interested only me; revolted to see a man younger than me wanting to govern me at all costs like a child; repulsed by his ease in promising, annoyed by so many appointments given and missed on his part, and by his fantasy of always giving new ones, to miss them again; embarrassed to wait for him uselessly three or four times a month, on days marked by himself, and to dine alone in the evening, after having gone to meet him as far as Saint-Denis, and having waited for him all day: my heart was already full of his many wrongs…

This last trait decided me; and, resolved to break with Diderot forever, I deliberated only on the manner; for I had realized that secret breaks turned to my detriment, in that they left the mask of friendship to my most cruel enemies.

Unlike Rousseau, Diderot lived a respectable family life, and was missed by his community. We read in We read in Grimm's Correspondence, March 1771:

 M. Diderot, master cutler in Langres, died in 1759, generally missed in his town, leaving his children an honest fortune for his state, and a reputation for virtue and probity desirable in any state. I saw him three months before his death. On my way to Geneva in March 1759, I passed through Langres on purpose, and I shall be proud all my life to have known this respectable old man.

He left three children: an eldest son, Denis Diderot, born in 1713, our philosopher; a daughter of excellent heart and uncommon firmness of character, who, from the moment of her mother's death, devoted herself entirely to the service of her father and his house, and for this reason refused to marry; a youngest son who sided with the Church: he is a canon of the cathedral church of Langres and one of the great saints of the diocese. He is a man of strange mind, of outrageous devotion, and in whom I have little faith in right ideas or feelings. The father loved his eldest son out of inclination and passion; his daughter, out of gratitude and tenderness; and his youngest son, out of reflection and respect for the state he had embraced.

Goethe, Schiller and the Impetuous of the Romantic Era

In the field of literature, Diderot’s belief in the power of storytelling and his emphasis on portraying the complexity of human nature can be seen in his novel, "Jacques the Fatalist." Through this work, Diderot explores the themes of determinism and free will, a religious theme he wrestles with due to his interest in Materialism, but his dedication to and recognition of the importance of morality.

Schiller and Goethe spoke of Diderot frequently, and Goethe introduced the German-speaking world to his works. Some of his works have been lost in French, but we have German translations thanks to Goethe. Goethe’s play The Natural Daughter may have been based on Diderot’s The Natural Son. In his letters, Goethe displays an incredible understanding of Diderot, and an appreciation of his Aesthetics:

On the other hand, I came across Diderot yesterday, who delighted me and moved my innermost thoughts. Almost every dictum is a spark of light that illuminates the secrets of art, and his remarks are so much from the highest and innermost of art that they also dominate everything that is only related to it and are just as much pointers for the poet as for the painter. If the writing does not belong to you yourself, that I can keep it longer and get it again, then I will prescribe it to myself.

Since I happened to come across the Diderot first, I have not yet moved on to the Staelische Schrift; however, both works are now quite a mental necessity for me, because my own work, in which I live and must live completely, limits my circle so much.

You can keep Diderot longer; it is a wonderful book and speaks almost more to the poet than to the visual artist, although it often shines before the latter with a powerful torch.

 It seems to me that Diderot is like many others who hit the truth with their sensibility, but sometimes lose it again through raison d'être. In aesthetic works, he still looks far too much at extraneous and moral purposes; he does not look for them enough in the object and in its representation. The beautiful work of art must always serve something else for him. And since the truly beautiful and perfect in art necessarily improves man, he seeks this effect of art in its content and in a certain result for the intellect, or for moral feeling. I believe it is one of the advantages of our newer philosophy that we have a pure formula to express the subjective effect of the aesthetic without destroying its character.

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