‘Psychologie’, ‘politique’. Encyclopédie, 1751-1765 (2021)

by Federico Soldani – 28th July 2021

The following are the entries – with bold added for emphasis – for the terms ‘psychology’ and ‘politics’ in the Encyclopaedia (‘Encyclopédie’, in full Encyclopédie, Ou Dictionnaire Raisonné Des Sciences, Des Arts Et Des Métiers, in English “Encyclopaedia, or Classified Dictionary of Sciences, Arts, and Trades”) co-edited by Denis Diderot and Jean-Baptiste le Rond d’Alembert and published initially between 1751 and 1765.

Only the initial part of the entry for ‘politics’ is reported here, while the full entry for ‘psychology’ is reported. There are links to the original French version as well as to an English translation for ‘psychology’.

According to the Encyclopaedia Britannica online “the 18th-century French encyclopaedia that was one of the chief works of the Philosophes, men dedicated to the advancement of science and secular thought and the new tolerance and open-mindedness of the Enlightenment. The Encyclopédie was a literary and philosophical enterprise with profound political, social, and intellectual repercussions in France just prior to the Revolution. Its contributors were called Encyclopédistes.”

“The Encyclopédie was inspired by the success of Ephraim ChambersCyclopaedia; or An Universal Dictionary of Arts and Sciences (London, 1728). Indeed, the work originated in an abortive attempt to put out a five-volume French translation of Chambers’ Cyclopaedia.

When this project collapsed in 1745, its intended publisher, André Le Breton, immediately embarked on plans for an expanded Encyclopédie. He secured the services of the mathematician Jean d’Alembert in 1745 and of the translator and philosopher Denis Diderot in 1746 to assist in the project. In 1747 Diderot undertook the general direction of work on the Encyclopédie, except for its mathematical parts, which were edited by d’Alembert. (D’Alembert resigned in 1758.) Seventeen volumes of the Encyclopédie’s text were published between 1751 and 1765; 11 volumes of plates were also published between the years 1762 and 1772, making a total of 28 volumes. These were supplemented in 1776–77 by five more volumes — four of text and one of illustration plates — and by two volumes of index in 1780, all compiled under other editors, since Diderot had refused to edit the supplementary materials. These seven volumes, plus the 28 prepared by Diderot, constituted the first edition of the Encyclopédie in 35 folio volumes.”

We have already encountered the name of Diderot on PsyPolitics as a possible author of the ‘Code de la Nature’ of 1755.

Along with the term ‘psychology’ – written by an unknown author – other terms were present in the Encyclopédie, in proximity, such as ‘psychagoges’, ‘psyché’, ‘psychomancie’ (and the related ‘nécromancie’), or elsewhere in the Encyclopédie such as ‘esprit’ or ‘pneumatique’.

The term ‘pneumatology’ did not have an entry of its own, however it was reported both under ‘psychology’ and in the introductory ‘Discours Préliminaire des Éditeurs’.

Along with the term ‘politics’, other terms such as ‘political authority’, ‘political liberty’, or ‘political law’ were present in the Encyclopédie.

“The group of writers that Diderot and d’Alembert assembled for the production of the Encyclopédie” – the Encyclopaedia Britannica online reports – “were at first relatively unknown, with the exception of Jean-Jacques Rousseau and Baron d’Holbach. But as both the fame of the Encyclopédie and the attacks upon it grew, distinguished and expert contributors were attracted, including A.-R.-J. Turgot, Voltaire, J.-F. Marmontel, and Jacques Necker. Diderot himself contributed innumerable articles, especially on philosophy, social theory, and the trades, proving to be both an energetic general editor and the driving force behind the crisis-ridden project. It was he who compiled and supervised the preparation of the work’s 3,000 to 4,000 plates, many of which vividly illustrated industrial arts and processes.”

Montesquieu, who died in 1755 in Paris, left behind an unfinished essay on taste for the Encyclopédie of Diderot and D’Alembert. In his major work ‘De l’esprit des loix’ (‘The Spirit of the Laws’, 1748), he developed a theory of the separation of powers which “had an enormous impact on liberal political theory, and on the framers of the constitution of the United States of America.”


PSYCHOLOGY (a), (Metaphysics) the part of Philosophy that deals with the human soul, defining its essence and accounting for its operations.

It can be divided into Empirical Psychology (or Experimental) and Theoretical Psychology.

The former draws on experience to develop its principles, by which it explains what takes place in the soul, while Theoretical Psychology, using these principles of experience to define the soul, infers then from this definition the diverse faculties and operations that befit the soul.

This double method, a posteriori and a priori combined, produces the most exact proof that anyone can claim.

Psychology contributes principles to various other parts of Philosophy: to natural law (b), to Natural Theology (c), to Practical Philosophy (d) and to Logic (e).

There is nothing more appropriate than the study of Psychology for fulfilling the most vivid of pleasures: a spirit that loves solid and useful knowledge. It’s the greatest delight to which man is susceptible here on Earth, consisting of the knowledge of the truth as it is bound to the practice of virtue; man cannot know how to arrive there without a prior knowledge of the soul, which is called to acquire this knowledge and to practice these virtues.


(a) PSYCHOLOGY, in ordinary courses, the doctrine of the soul is only a part of Pneumatology or the doctrine of spirits, which is itself only a part of Metaphysics. But Mr. Wolff in the philosophical disposition of his course, made Psychology a distinct part of Philosophy, to which he devoted two volumes; one for Empyric Psychology; the other for Reasoned Psychology, & he placed this deal immediately after his Cosmology, because it follows principles for almost all the other parts, as the following notes justify it.

(b) Natural law. We demonstrate in natural law, what are the good and the bad actions. Now the reason for this qualification of actions can only be deduced from human nature, and in particular from the properties of the soul. Knowledge of the soul must precede the study of natural law.

(c) Natural Theology. We can only arrive at the notion of divine attributes by freeing up the notion of the properties of our soul, of its imperfections & its limitations. We must therefore begin by acquiring in Psychology, distinct ideas of what suits our soul, to abstract from them the general principles, which determine what suits all minds, and therefore God.

(d) Practical Philosophy. The main object of Ethics or Morality is to engage men to practice virtues, and to flee vices, that is to say, to determine in general the appetites of the soul in a suitable manner. Who, then, does not see that this determination of appetites requires that we distinctly represent the substance in which they reside?

(e) Logic. Although for particular reasons, we have kept to Logic the first rank among the parts of Philosophy, it does not fail to be subordinated to Psychology, as long as it borrows from it principles without which it could not make sense of the difference of ideas, nor to establish the rules of reasoning which are founded on the nature and the operations of the soul.


POLITICS, (Philosophy) Political philosophy is that which teaches men to behave with prudence, either at the head of a state or at the head of a family.

This important part of Philosophy was not neglected by the ancients, and especially by the school of Aristotle. This philosopher raised at the court of Philippe, and witness to those great political blows which made this king so famous, did not miss such a favorable opportunity to penetrate the secrets of this science so useful and so dangerous; but he did not amuse himself, like Plato his master, by giving birth to an imaginary republic, nor by making laws for men who do not exist: on the contrary, he made use of the light which he drew from the familiar trade which he had with Alexander the Great, with Antipater, and with Antiochus, to prescribe laws in conformity with the state of men, and the nature of each government. See its morality & its politics.

However estimable the precepts one finds in the writings of this philosopher, it must be admitted that most of them would not be well suited to governing the states which now share the world. The face of the earth has undergone so many revolutions, and customs have changed so greatly that what was very wise at the time when Aristotle was writing would be nothing less than that if it were now put into practice. And this is undoubtedly the reason why of all the parts of Philosophy, politics is that which has undergone the most changes, & why, among the great number of authors who have treated of this science, there is none who did not propose a different way of governing.

We will only speak here of those of the moderns who have made themselves most famous for their works on politics.


The title page of the Encyclopédie- Wikipedia

Extract from the frontispiece of the Encyclopédie (1772). It was drawn by Charles-Nicolas Cochin and engraved by Bonaventure-Louis Prévost. The work is laden with symbolism: The figure in the centre represents truth—surrounded by bright light (the central symbol of the Enlightenment). Two other figures on the right, reason and philosophy, are tearing the veil from truth – Encyclopédie – Wikipedia


Cite this article as: Federico Soldani, "‘Psychologie’, ‘politique’. Encyclopédie, 1751-1765 (2021)," in PsyPolitics, July 28, 2021, https://psypolitics.org/2021/07/28/psychologie-politique-encyclopedie-1751-1765-2021/.

Last Updated on July 28, 2021 by Federico Soldani

Leave a Reply