The Dictionary reasoned of sciences, arts and the trades, called more usually the Encyclopedia of Diderot and Alembert occupies an exceptional place among the works which marked the history of Western civilization. It belongs par excellence to the Age of Enlightenment and its triumphing rationalism. One of the principal merits of his/her some a hundred and fifty collaborators is to have widened the rationalist field of reflection to “useful arts” in the hope of producing “a revolution in the spirits”.

In its preliminary Speech, of Alembert places the Encyclopedia under the eminently rationalist sign of “the order and the sequence of human knowledge”. Diderot, in its turn, underlines in the article “Encyclopedia” which it acts of a company deeply anchored in a “philosophical century”, which seeks “to return to sciences and arts a freedom which is so invaluable for them”. Following the example of its true ancestor, the historical and critical Dictionary of Pierre Bayle (1697), which hustled in its time many prejudices while preaching for the tolerance and against the superstition, and who affirmed the possibility of being a virtuous atheist, the work - 17 volumes of text and 11 volumes of engraved boards of which the first appeared in 1751 and eleventh and last volume in 1772 - was given for objective to produce a “revolution in the spirits”.

Reactions to the publication

At the beginning of its publication, the Encyclopedia will raise violent attacks on the part of its many detractors, who consider it subversive: since 1751, the Jesuits express themselves in the Newspaper of Trévoux of the P. Berthier, and three years later the religious order and policy are defended against the encyclopedists by the review the literary Year of Fréron. The intransigence of the Jansenists against what they perceive like atheist and materialist in the Encyclopedia unchains in New the ecclesiastics and the weekly Critic. Malesherbes, director of the Bookstore and which, in the royal entourage, supports the company, polemical with Buffon in its Observations on the natural history.

As for the Protestant press, it gives to the Encyclopedia a reserved support; the newspapers printed in France (the Advertisements, Mercure de France, the Gazette) are satisfied to inform without taking party; the Newspaper of the scientists gives his assent with the scientific and technical part, but takes care well not to evoke the philosophical and political contents work. Only the encyclopedic Newspaper of Pierre Rousseau and the literary Correspondence of Grimm take make and cause for the work, struck prohibition, in 1752, by a stop of the Council of the king.

The philosophical base

Triple influence gives its bases to the philosophical doctrines of the Encyclopedia: the theories of the knowledge of Descartes, Bacon and Locke are the primary sources of the empiricist sensualism which underlies the work; this one is subject to also the influence of the spinozism and that of a political philosophy which is registered, approximately, in a moderate monarchy.

Homage to Descartes
According to the definition that Diderot gives some, which as regards history of philosophy holds its radical skepticism - pyrrhonien - of Bayle and Fontenelle, the philosopher is an eclectic thinker, which presses with the feet the prejudices, the traditions, the universal assent, the authority, and which dares “to think of itself, to go back to the general principles clearest, to examine them, discuss them”. Articles “Philosophy”, “Authority (in the speeches and the writings)” and “Eclecticism”, which describes the philosopher as that which under investigation applies sciences while seeking to know the effects by their causes and their principles, pay homage to Descartes clearly.

A method referring to Bacon
The will to shake the yoke of the opinion and the authority, to bring back each thing to its own principles aims at returning to the reason all its rights. It implies, in fact, that the reason must give up the systematic mind, in particular the established religion, which are the violent criticism object in the articles “Fanaticism” and “Persecute”, and especially in the article “Priest”, which sign of Holbach.

But the abolition of the old frame of reference is accompanied obligatorily by the choice of a new method of scientific investigation. Drawing aside from the start the Cartesian inneism (“there is innate only faculty to feel and think, all the remainder is acquired”), the encyclopedists affirm that only the sensitive one can lead to the abstract. Obviously, this method refers to Bacon and its experimental process, in virtue of which science is “the image of the truth: because the reality of existence and the truth of knowledge are only one and even thing, and do not differ more between them that the direct ray and the considered ray”. This apology for science goes hand in hand with the engagement of many doctors among the scientific collaborators, but also with a large number of article devoteds to with the animal world.

Materialism of Diderot
The development of a philosophy materialist in the columns of the Encyclopedia is directly related to work of Diderot, which, after having admitted, in the philosophical Thoughts, the existence of a natural harmony and a compensatory mechanism of the disorders, will give up the idea that the universal order is regulated like a clock. Evoking irregular agitations of the ocean of the Universe, it ends up admitting that the world results from the “fortuitous jet” of the atoms. The “vitalistic” materialism of Diderot is reflected in particular in the articles “Atomism”, “Corpuscular” and “Epicureanism” - this last considering a matter heterogeneous and not created - like in the articles “Leibnizianisme” and “Hobbisme”, according to which there exists an organic relationship between the simple part and the whole. Under the impulse of its project superintendent, the work also affirms continuity between raw material and living matter, and underlines the perenniality of the matter and its tendency to change (articles “Imperfect”, “Imperishable” and “Nothing”). Just as the sights materialists of the Latin poet Lucrèce govern the very important “Animal” article, where the relative questions with the evolution of the species are tackled, in the same way the reports of the heart and the body are inspired largely by the Treaty of passions of Descartes and the vision materialist of Mettrie and the Meslier priest. Thus the article “Affection” establishes it a bond of interdependence between the psychological disorders and the organic disorders.

Private amorality, civic morals
The consequences of these philosophical doctrines are summarized in an amorality without ambiguity (in particular in the article “Freedom”). But, paradoxically, the Encyclopedia defends at the same time the amoral behavior and that for the virtue, which is developed since morals is placed from the political point of view. Whereas it tolerates the amorality of the private individual, it preaches the virtue of the citizen, as testifies some the “Chinese” article: “There is one principle of control: it is to carry in all sincerity, and to conform of all its heart and all its forces to universal measurement; do not do with others what you do not want that one makes you.”

The political theory

Many articles relating to the human society (“Agriculture”, “Political authority”, “Corruption”, “Right natural”, “natural Equality”, “Nation”, “Oppressors”, “People”, “Representatives”, “Theocracy”, “Tolerance”, “Tyrant”…) the men like beings equipped with a natural sociability describe. With this first key notion of the policy that of general interest is added, which rests on the idea that mankind constitutes only one and even company: this general society is naturally produced by the needs and the feelings which link the men and create between them relations of reciprocal utility.

The state of nature
The research of the good and happiness is at the origin of all the human acts, and if a man acts badly, it is that it cannot choose the adequate means to obtain them. As underlines it the “Socratic” article, signed by Diderot: “It is the spirit which leads us badly: we are criminal only because we judge badly; and it is the reason, and not the nature which misleads us.”

Before meeting in company, the men live in the state of nature, that the Encyclopedia presents sometimes like a theoretical assumption, sometimes like a historical fact. Adhering to the thought of Grotius, the encyclopedists affirm that in the absence of social laws and of a true jurisprudence it is the natural right which reigns “in the social actions of the people wild and cruel and in the tacit agreements of mankind between them”.

The pact of tender - the contract by which the men commit themselves obeying the will of a sovereign in order to put an end to the war of all against all - confers to the prince an authority on the nation (article “Hobbisme”), however “no man received nature the right to order with the others” (article “Political authority”).

Equality and the established order
Contrary to Locke, the Encyclopedia does not grant the right of insurrection to the citizen (“In times of disorders, the citizen will stick to the party who is for the established system”, the article “Citizen declares”) and remains in December of the position lockienne as for the extent of the rights reserved to the people. It does not adopt either the design rousseauist of the equality. Indeed, if the natural equality is marked with force by the knight of Jaucourt in the article of the same name, the political equality, it, is clearly rejected like a dangerous Utopia, which does not take account of the need for maintaining “conditions different, ranks, honors, distinctions, prerogatives, subordinations, which must reign in all the governments”.

Under the terms of a vast plan of reform, which constitutes the true originality of the Encyclopedia in political matters, the philosophers would have to light the people on his rights and to found the prosperity and the freedom of the progress of arts and industry. As the article “Man underlines it (political)”, freedom is the essential condition of economic progress: “There will be industrial men if they are free.”

Arts and trades

The reflection on arts and trades constitutes the true finality of the Encyclopedia, which had a considerable influence on the industrial revolution. The work holds a philosophical treatment the “mechanical arts”, in their attaching the same importance as to “sciences more the sublimes and the most honoured arts”. Thus, the article “Art” pays a homage solemn to Bacon, which he regards as “one of the first geniuses of England looked at the art history mechanics as the most important branch of the true philosophy”.

The a hundred and fifty collaborators of the Encyclopedia - Diderot, of Alembert, Condillac, Daubenton, of Holbach, Marmontel, Montesquieu, Rousseau, Turgot, Voltaire, etc -, which attended the rise of mechanization and the first manufactures, systematically got busy to describe in detail the various manufacturing processes, by using with the highhest degree of accuracy the specific vocabulary of each trade. The article “E-mail”, remarkable in this respect, was practically written under the dictation of a craftsman.

If the Encyclopedia and the “movement encyclopedist” that it generated could be described rightly as revolutionists, it is that, through the description of arts and trades, they contributed to the advance of new technologies. In a more general way, the encyclopedists opened the way with economic progress by connecting the mechanical arts to philosophical and political principles.