Notes to Part I
1. A list of some fifty men who had contributed in one way or another to the first volume of the Encyclopedia makes up the last part of the Discourse. With each new volume until the final official suppression of the work in 1759, the number of contributors grew in proportion to the enthusiasm for the project among the members of the republic of letters. Very few of the contributors to the first volume of the Encyclopedia, except d’Alembert, had achieved a widespread reputation by 1751, and neither Voltaire nor Montesquieu had yet been recruited to the encyclopedic project.
2. D’Alembert’s note as follows: “This Prospectus was published in the month of November, 1750.”
3. Most of that Prospectus of November, 1750, which announced the enlarged Encyclopedia and invited subscribers, is incorporated into the last part of the Discourse. D’Alembert refers to the attacks of the Journal de Trévoux (see notes 13 and 14 of the Introduction). Diderot had promised Father Berthier that d’Alembert would answer all the questions raised in the Journal, and many others. See Diderot, Correspondance, ed. G. Roth, I, 106.
4. Later editions: “The work which we are beginning (and which we wish to finish). . . .”
5. It is essential to remember throughout this work that the word “science” is by no means restricted to natural science. According to Diderot’s definition in the Encyclopedia, if the object of a discipline is only contemplated from different approaches, the technical collection and disposition of observations relative to that object are called “science.” Thus theology, history, and philosophy, as well as physics and mathematics, are sciences. If the object of a discipline is something executed, the technical collection and disposition of rules according to which it is executed is called “art.” By this definition ethics is an art. See “Art,” Encyclopédie, I, 713–14.
6. I.e., “Systematic” Dictionary.
7. The rationalist assumption of the unity of knowledge here makes its appearance at the outset of the Discourse and, indeed, is the very foundation of the encyclopedic project.
8. A comparison of d’Alembert’s wording with the following lines in Condillac’s Essai sur l’origine des connoissances humaines (Essay Concerning the Origin of Human Knowledge, 1746) gives one indication among many of d’Alembert’s debt to the work of Condillac throughout the Discourse:
Our first object, which we should never lose from sight, is the study of the human mind—not to discover its nature, but to learn to know its operations, to observe how they are combined and how we ought to use them in order to acquire all the intelligence of which we are capable. It is necessary to go back to the origin of our ideas, to work out their generation, to follow them to the limits which nature has prescribed for them, and by these means to establish the extent and limits of our knowledge and renew all of human understanding. [ Oeuvres philosophiques de Condillac, ed. Georges Le Roy (Paris, 1947), I, 4.]
9. The “substantial forms” and “occult qualities” to which d’Alembert refers are technical concepts which he alleges are derived from ancient philosophy and were incorporated into the medieval scholastic philosophical-theological system. The philosophes disagreed contemptuously with the scholastics about what was an adequate explanation of any given phenomenon. One of the ways the scholastics “explained” physical phenomena, for instance, was by postulating the existence of “occult qualities” (unknown causes of manifest effects) hidden within bodies. These scholastic inventions are summarily dealt with as being utterly useless explanations of anything in the article “Quality (Metaphysics),” Encyclopédie, XIII, 651, which was probably written by d’Alembert. The term “substantial form” is defined in d’Alembert’s article “Substantial Form,” Encyclopédie, VII, 176, as a “barbarous term of old scholastic philosophy which was principally used to designate alleged material beings which were nevertheless not matter.”
10. Locke made the classic attack upon innate ideas in his Essay Concerning Human Understanding (1690), ed. A. C. Fraser (2 vols.; Oxford, 1894), I, cxvi and 38 ff.:
[They took men away] from the use of reason and judgement, and put them on believing and taking upon trust, without further examination. . . . Nor is it a small power it gives one man over another to have the authority to be the dictator of principles and teacher of unquestionable truths, and to make a man swallow that for an innate principle which may serve to his purpose who teacheth them [I, 116].
11. D’Alembert reproduces here Locke’s refutation of the existence of innate ideas, which appears in the following lines of the Essay Concerning Human Understanding (I, 38): “Men barely by the use of their natural faculties, may attain to all the knowledge they have without the help of any innate impressions; . . .” If one decides that there are no innate ideas, the operations of the mind become susceptible to the precise and measurable critical analysis of physical sense impressions and the simple ideas they produce.
12. This is a reduction of the famous proof of Descartes: “I think; therefore I am,” to “I have sensations; therefore I am.” The Cartesians’ clear and distinct ideas are replaced by the empiricists’ clear and distinct sensations as the basic common denominator of all thought and truth.
13. This phrase is obscure: “. . . les affections involontaires qu’elles nous font éprouver, comparées avec la détermination volontaire qui préside à nos idées refléchies, et qui n’opère que sur nos sensations mêmes: . . .” It is clarified in d’Alembert’s article “Corpsuscle,” Encyclopédie, IV, 262, where he says proof of the existence of matter (bodies) is based “on the involuntary effects which they produce in us compared with our voluntary reflections on these same sensations.”
14. Here d’Alembert wrestles with the problem that dogged philosophers from Descartes on who were concerned with the relation of the mind to the exterior world (matter). How can we, limited in all our knowledge to the evidences of our sensations, know that they represent an existence outside themselves and outside ourselves? Descartes and Malebranche state that it is God who assures the harmony between our ideas and the external world. Berkeley resolves the question by denying the existence of matter and asserting that all is idea. For him it is the will of God that puts order, coherence, objectivity, and necessity in the ideas of experience. D’Alembert falls back upon a pragmatic solution to a problem that is logically insoluble in the terms in which it is posed. His critic in the Journal des Sçavans, October, 1751, pp. 219–20, complained that d’Alembert did not explicitly assert that God intervenes on the occasion of the sensations and puts in our minds the direct ideas of things and also that God is responsible for our irresistible impulse to believe there is a causal relation between our sensations and the ideas we have of them. An article by a Huguenot theologian in the Dutch edition of the same Journal, November, 1751, pp. 404–31, defends the philosophy of Descartes and the Cartesians at great length against d’Alembert’s criticisms in the Preliminary Discourse.
15. Montaigne, Essais, II, Chap. XXV, 133 in the Pléiade edition of Oeuvres complètes, (Paris, 1962).
16. “Soul” (âme), throughout the Discourse, means that part of us that thinks, judges, wills, and experiences “feelings” and emotions. For d’Alembert and his contemporaries the idea of the “soul” includes our intellectual nature (mind) as well as our emotional and moral ones; it is the part of us that perceives.
17. D’Alembert probably refers here to the Stoics, although the line might be applied equally well to the doctrine of optimism which came under widespread fire by the philosophes, the most famous attack being Voltaire’s Candide. The next line doubtless refers to the Epicureans, or to the corruptors of the Epicurean ethics. See Montaigne, Essais II, Chap. xii, 469. The same point is made in I, Chap. xiv, 55.
18. See Introduction for the utilitarian implications of this paragraph.
19. At this point we move into a section where d’Alembert, in a way not quite parallel to Locke or Condillac, considers the way ideas and knowledge must have developed historically in the earliest collective experiences of mankind, and we see him combining the “metaphysical” with the historical approach to the origin and progress of our ideas, at the same time dealing with the genealogy of ideas in the “isolated mind” and the development of certain ideas resulting from the historical social experience of human beings.
20. This basic “natural law” is that which naturally leads men to preserve themselves from pain or death at the hands of those who are stronger than they. Ultimately, it is the natural law of social self-preservation that is stamped upon everyone, and it involves the necessity of resistance to oppression. Thus, the fundamental natural law of ethics and society is, for d’Alembert, an empirical fact in the history of humanity. The first laws of organized societies were designed to limit oppression; thus they derive from the natural law of self-preservation, protecting the members of society as well as possible from pain and death at the hands of the strong. This seems almost to be a Hobbesian view of the natural state of man and the origins of law, government, and the ideas of right and wrong.
21. This was an especially controversial passage and was roundly attacked for its impious implications in the Journal des Sçavans, October, 1751, p. 220, where the author asks how an isolated man learns of his duty to God and himself if the ideas of morality derive only from social experience.
22. One can see a Cartesian inspiration in parts of this passage. However, in contrast to Descartes, who goes from mind (“I think, therefore I am”), to God, to body, to the rest of the material world, d’Alembert starts from physical sensations, material facts, and the demands of the body. Then he moves to the historical formation of society and ideas of ethics, thereafter to knowledge of the soul, and finally to God. Again he adds historical considerations and Lockeian sensationalism to the timeless Cartesian metaphysical derivation of the origin of ideas. He defends this sequence later against the complaints of the pious by claiming that experience, history, and reason show that the notions of vices and virtues have preceded knowledge of the true God among the pagans ( Oeuvres, I, 14–15).
23. D’Alembert’s abstract terminology makes it difficult to be certain exactly what he means in this passage. Condorcet gives an indication of what is meant by the “first combining” in his Esquisse, or Sketch for a Historical Picture of the Human Mind (1794; tr. June Baraclough, New York, 1955), pp. 15–16:
The first fruits of continuous association are a number of arts, all concerned with the satisfaction of simple needs. They include the making of weapons, cooking and construction of the utensils necessary for cooking, preserving food and providing against those times of the year when fresh supplies are unobtainable. . . .
24. In the next several paragraphs d’Alembert launches into an exposition of his philosophic and scientific method to which he returns again and again in the Encyclopedia and in his other works. It is a classic statement of what Cassirer calls the philosophy of the Enlightenment. First the intellect analyzes the objects of rational study into the properties that constitute them, in order to study each of these properties in isolation; then it puts them together once more. Through the process of treating all the data of the disciplines analytically and synthetically, the mind attempts to discover the simple facts or simple laws behind them, which d’Alembert prefers to call “principles.” As he and other philosophes were well aware, this method had produced the triumphs of mathematics and physics in the seventeenth and eighteenth centuries, among them d’Alembert’s own Traité de dynamique (1743) and Traité de l’équilibre et du mouvement des fluides (1744). They hoped it would produce similar triumphs in the other disciplines. For a further elaboration, see d’Alembert’s excellent article “Analytic,” Encyclopédie, I, 403–4.
25. Compare with d’Alembert’s “Introduction au Traité de dynamique ” (1743), Oeuvres, I, 393–94:
. . . in order to have a clear idea of movement we cannot avoid the necessity of differentiating, at least mentally, two sorts of extension: one which is regarded as impenetrable and which constitutes what is properly called body; the other which, being viewed simply as extension, without examining whether it is penetrable or not, is the measure of the distance from one body to another, and can serve to determine the movement or lack of movement of body.
26. Later editions: “more familiar.”
27. The definitions of number, arithmetic, and algebra in this paragraph and the succeeding one are derived from Newton (Arithmetica universalis). The meanings of the difficult passages in these two paragraphs are clarified in d’Alembert’s article “Arithmetic,” Encyclopédie, I, 675. D’Alembert uses Newton’s definition of number as being nothing more than a relationship (rapport), and the meaning of several phrases here becomes clearer if the word “number” is substituted for “relationship.” Thus, in the next to the last sentence in this paragraph, for example, two is the unique relationship (number) which results from the comparison of the relationships six and four in the following calculation: 6 − 4 = 2.
28. See “Universal Arithmetic,” Encyclopédie, I, 675–76. We can indicate numbers by general expressions (in algebra these are alphabetical letters). This is what is meant in the phrase “expressing these relationships [numbers] in a universal way.” For instance, the letter a can be the universal expression for any number and b for any other, etc. We can manipulate and combine these alphabetical general numbers in different ways in order to reduce them to their simplest expression possible. See the definition of algebra in the Chart of Knowledge.
29. For example, the movement of the planets, whose ultimate cause is unknown, although the laws of their movement are known, or at least measurable.
30. This sentence is a direct quotation from d’Alembert’s “Introduction au Traité de dynamique ” (1743), Oeuvres, I, 392. Aram Vartanian, in Diderot and Descartes (Princeton, 1953), p. 157, sees this part of the Discourse as a continuation of Descartes’ rationalistic ideal of relating the totality of physical data to a unique cause. Condillac seems to have incorporated ideas from this same passage of d’Alembert’s almost word for word into the first paragraph of his Traité des systèmes (1749), Oeuvres, I, 121:
A system is nothing more than the arrangement of different parts of an art or a science in an order in which they all support one another, and in which the last are explained by the first. Those which explain the others are called principles; and the system is so much the more perfect as the principles are fewer in number: it is even to be hoped that one could reduce them to a single one.
31. Chemistry would fall under this category of General and Experimental Physics.
32. Later editions: “the science of the properties of.”
33. Throughout this discussion we have a restatement of several points of Condillac’s Traité des systèmes, in Oeuvres, I, 199 ff.
34. Throughout the Discourse, d’Alembert is reflecting a major concern of Bacon, Descartes and Locke, who had all been occupied with the question of establishing the limits of our knowledge so that philosophers might most profitably expend their efforts on what can be known through reason, rather than wasting them, in flights of speculation, imagination, and superstition, on what cannot.
35. Later editions: “all the sects.”
36. This celebrated paragraph comes directly from d’Alembert’s “Introduction au Traité de dynamique,” Oeuvres, I, 391–93, showing he had a taste for metaphysical and philosophical statements well before he wrote the Discourse.
37. In these paragraphs, as d’Alembert moves from a description of the unity of geometry to the statement of the assumption of unity in all phenomena, we have a most perfect exposition of the marriage of the “geometric spirit” with the empiricism for which Condillac gave the theoretical definition in his Traité des systèmes (1749). There Condillac asserted that the only legitimate system was one that explained facts by facts, and the best system was one in which one fact would explain all the others.
38. In this rather confusing paragraph, d’Alembert is distinguishing between the faculty for thinking logically, which people have always had, and the formal discipline (Logic) that analyzes and makes explicit its rules. Logic is only one of the several meanings attached to the words “reason” and “reasoning” in the Enlightenment. The term “reason” came to apply to the entire method of analysis and synthesis described up to this point in the Discourse.
39. D’Alembert uses at least two different meanings for the word “genius” in this Discourse: the older notion of genius as some excellent quality which certain persons had the good fortune to share (found in the phrase: “He has genius”), and the more romantic one beginning to appear in the eighteenth century, which assigns the name “genius” to a person of transcendent creativity, intellect, or ability (see [a, b, c, d, e, f, g, h]). Saint-Lambert’s celebrated article “Genius,” Encyclopédie, VII, 582–84, carries through this latter definition in detail. In addition d’Alembert defines genius as a “feeling that creates”. For a lucid discussion of the concept of genius in eighteenth-century France, see Herbert Dieckmann, “Diderot’s Conception of Genius,” Journal of the History of Ideas, II (1941), 151–82.
40. Later editions: “formation.”
41. D’Alembert reproduces here some of the interest in the development of language which Condillac found to be of central importance in his discussion of ideas (Part Two of his Essai sur l’origine des connoissances humaines , in Oeuvres, I, 60 ff., which in turn owes something to Locke’s discussion of signs and Warburton’s discussions of the origins of language). The history of the development of signs is, in effect, the history of ideas, starting in earliest times with words for individual things, then moving to abstract words involving general properties of objects. These also indicate the birth of first the arts and then the sciences. D’Alembert carries on the discussion of signs in the Encyclopedia (cf. “Character,” vol. II).
42. D’Alembert enlarged upon these thoughts in his stinging attack upon the sterile instruction in rhetoric in his controversial reforming article “College,” Encyclopédie, III, 634–37. This article was highly offensive to the Jesuits, who rightly construed it as an attack on the schools of secondary education, which they practically monopolized in France.
43. D’Alembert was the author of several articles concerning Chronology and its relationship to Astronomy in the Encyclopedia, e.g., “Calendar,” vol. II, and “Chronology,” vol. III. Later d’Alembert developed and enriched his conception of the nature and importance of the study of history. He became more and more explicit in his appreciation of the value of its philosophic study for the progress and understanding of the sciences. Also, in his later exposition, history becomes essential for the progress of the “empirical” study of human ethics. In his splendid article “Elements of the Sciences,” Encyclopédie, V, 495–96, he expounds the value of the study of history for the philosophic treatment of the moral universe. The philosopher, he says, regards history as “a collection of moral experiments made on mankind,” which he collects, compares, and observes in order to discover the principles, just as a doctor compares and collects medical observations.
44. For the encyclopedists Philosophy ceases to be a particular form of knowledge or reflection; it becomes truly the sum of reasoned human knowledge in all fields, and it is not far from being identified with the Encyclopedia itself. See Hubert’s discussion of the subject in Les Sciences sociales dans l’Encyclopédie, p. 321.
45. Later editions: “what they lose of attractiveness in this latter case. . . .”
46. D’Alembert’s treatment of those areas of human thought that have to do with creative imagination, the fine arts, reflects a continuing pre-occupation of eighteenth-century authors with the traditions of seventeenth-century classicism. (See [Part II,] n. 8.
47. La belle Nature is defined by Jaucourt ( Encyclopédie, XI, 42) as nature embellished and perfected by the fine arts for use and pleasure. The artist makes a choice of the most beautiful parts of nature to form an exquisite whole, which would be more beautiful than nature itself. It is not direct imitation, but rather the representation of nature as it could be.
48. Rousseau complimented d’Alembert on his theory of musical imitation, which he found “très-juste et très neuve.” Correspondance générale de J.-J. Rousseau, ed. Th. Dufour (Paris, 1924), letter of June, 1751, II, 11–12. However, Rulhière energetically attacked the same passage as being an example of what happened when geometers and scientists came to feel they were true judges of music because they understood the physics of sound (quoted in A. R. Oliver, The Encyclopedists as Critics of Music [New York, 1947], p. 94). D’Alembert’s notions were perfectly typical of those of the other encyclopedists who, as Oliver writes, “believed that all music was one and that its principal object was to ‘paint.’ . . . All this thinking grew out of the encyclopedists’ lamentable attempt to force music into the imitation-of-nature thesis” (p. 61). See [Part II,] n. 56 for a discussion of d’Alembert as music critic.
49. D’Alembert makes the same distinction here that Diderot makes between an art and a science (see [Part I,] n. 5.
50. This reference to the “social contract” adds one more fragment to the very sketchy treatment of political theory in the Discourse (see [Part I,] n. 20, p. 12).
51. These are all technical watchmakers’ terms whose definitions can be found in the Encyclopedia or in an unabridged dictionary.
52. Eloquence, poetry, music, painting, sculpture, architecture, and engraving are in this category.
53. The word “evidence” as used here may be defined as the condition of being self-evident.
54. Later editions: “operations.”
55. “Natural law,” as we have seen, means for d’Alembert the natural fact that men in society, in their urge for self-preservation and freedom from pain, have always naturally resisted oppression. This fact of human experience is, of course, very close to the level of feeling. The fact of oppression and the urge for self-preservation and freedom from pain seem in d’Alembert’s mind to have stimulated an almost automatic reaction in the feelings of human beings that responds directly to right and wrong actions—conscience. See [Part I,] n. 20 and our Introduction.
56. The anonymous author of the long review of the Discourse in the Journal des Sçavans, October, 1751, p. 220, took exception to this statement in the following terms:
And [in the Discourse ] ethical truths have only an evidence of the heart, founded on the sentiment of the conscience, and completely different from the evidence of the intelligence attributed to speculative truths. Are not the first principles of ethics of an evidence recognized by the light of Reason? Do men have no rule for their action other than conscience? Has M. d’Alembert realized the frightful consequences of such a principle?
57. Later editions: “l’esprit” instead of “l’âme.”
58. The explanation of the chart begins on p. 143. This section was anticipated in the following passage cited by Lovejoy (p. 232) from Thomas Sprat’s History of the Royal Society (1667), p. 110:
Such is the dependence amongst all the orders of creatures; the animate, the sensitive, the rational, the natural, the artificial; that the apprehension of one of them, is a good step toward the understanding of the rest. And this is the highest pitch of humane reason: to follow all the links of this chain, till all their secrets are open to our minds; and their works advanc’d or imitated by our hands. This is truly to command the world: to rank all the varieties and degrees of things so orderly upon one another, that standing on the top of them, we may perfectly behold all that are below; and make them all serviceable to the quiet and peace and plenty of Man’s life. . . .
59. This paragraph seems to be a direct application of Buffon’s definition of biological continuity to the entire range of encyclopedic knowledge. It appears to be based, in much the same vocabulary, on Buffon’s “Premier Discours” to his Histoire naturelle, whose first three volumes appeared in 1749 ( Oeuvres philosophiques de Buffon [Paris, 1954], I, 7–26), and it is one of the most striking expressions in the eighteenth century of the notion of continuity described by Lovejoy in The Great Chain of Being. D’Alembert returns to the subject in the article “Cosmology” in the Encyclopedia and in his Élémens de philosophie (1759). The function of the philosopher, according to him, is to add new links and to fill in the gaps between them as much as possible so that our knowledge can be made ever more useful in improving the human condition.
60. Later editions: “this Discourse.”
61. In his Premier Discours Buffon makes a sweeping attack on the great systematizers of biology in the seventeenth and eighteenth centuries, particularly Linnaeus and Tournefort. The system of nomenclature of the latter was generally adopted in the Encyclopedia.
62. Later editions: “. . . they did not think. . . .”
63. This passage is largely to justify altering Bacon’s order of arrangement of knowledge which placed imagination before reason. Note that “geometer” in d’Alembert’s definition is a term that includes all mathematicians and is not strictly limited to practitioners of geometry alone. (See the article “Geometer,” Encyclopédie, VII, 627.)
64. D’Alembert was taken to task in the Journal des Sçavans, October, 1751, pp. 222–23, for subordinating Theology to Philosophy and for having degraded the study of natural religion. He defended himself in the later editions of the Discourse.
65. “Beaux esprits” in this context could be rendered “Creative Artists.” It includes writers, composers, painters, and practitioners of the various arts of imagination.