The Age of Voltaire

by Will Durant

  Hence without parents, by spontaneous birth,

  Rise the first specks of animated earth. …

  Organic life beneath the shoreless waves

  Was born and nursed in ocean’s pearly caves;

  First, forms minute, unseen by spheric glass,

  Move on the mud, or pierce the watery mass;

  These, as successive generations bloom,

  New powers acquire, and larger limbs assume;

  Whence countless groups of vegetation spring,

  And breathing realms of fin and feet and wing.127

  So life evolved from marine forms to amphibians in the ooze, and to the numberless species of sea and land and air. The poet quoted Buffon and Helvétius on features of the human anatomy indicating that man formerly walked on four feet and is not yet fully adjusted to an erect posture. One species of ape emerged to a higher state by using the forefeet as hands, and developing the thumb as a useful counterforce to the fingers. In all the stages of evolution there is a struggle among animals for food and mates, and among plants for soil, moisture, light, and air. In this struggle (said Erasmus Darwin) evolution took place by the development of organs through efforts to meet new needs (not by the natural selection of chance variations favorable to survival, as Charles Darwin was to say); so plants grow through efforts to get air and light. In Zoonomia the doctor foreshadowed Lamarck: “All animals undergo transformations which are in part produced by their own exertions, in response to pleasures and pains, and many of these acquired forms or propensities are transmitted to their posterity.”128 So the snout of the pig was developed for foraging, the trunk of the elephant to reach down for food, the rough tongue of cattle to pull up blades of grass, the beak of the bird to snatch up seeds. To which the doctor added a theory of protective coloration: “There are organs developed for protective purposes, diversifying both the form and color of the body for concealment and for combat.”129 And he concluded with a majestic glance over eons:

  From thus meditating upon the minute portions of times in which many of the above changes have been produced, would it be too bold to imagine, in the great length of time since the earth began to exist, perhaps millions of years before the commencement of the history of mankind, that all warm-blooded animals have arisen from one living filament, which the first great Cause imbued with animality, with the power of acquiring new parts, attended by new propensities, directed by irritations, sensations, volitions, and associations, and thus possessing the faculty of continuing to improve by its own inherent activity, and of delivering down those improvements by generation to posterity, world without end?130

  “It is curious,” wrote Charles Darwin, “how largely my grandfather … anticipated the views and erroneous grounds of opinion of Lamarck in his Zoonomia.”131 Perhaps the grandfather would not admit that he was on the wrong track. In any case he had expounded a theory that is not yet dead, and in his genial way he had struck a blow for evolution.

  IX. PSYCHOLOGY

  From minerals to plants to animals to man the scientific quest advanced. Armed with the microscope, and spurred on by the needs of physicians, a growing fraternity of students peered into the human body, and found its organs and functions indisputably similar to those of the higher beasts. But there still seemed to be a break in the chain of being: nearly everyone agreed that the mind of man differed in kind, as well as degree, from the mind of animals.

  In 1749 David Hartley, an English clergyman turned physician, ventured into the gap by founding physiological psychology. For sixteen years (1730–46) he gathered data; then, in 1749, he published his Observations on Man. Ambitious to find a principle governing the relations of ideas as Newton had proposed a principle governing the relations of bodies, Hartley applied the association of ideas to the explanation not only of imagination and memory, as Hobbes and Locke had done, but also of emotion, reason, action, and the moral sense. He pictured sensation as first a vibration in the particles of a nerve stimulated by an external object, and then as the transmission of this vibration along the nerve to the brain, like “the free propagation of sounds along the surface of water.”132 The brain is a mass of nerve fibrils whose vibrations are the correlates of memories; one or more of these fibrils is agitated by an incoming vibration associated with it in past experience; this reverberation is the physiological concomitant of an idea. For every mental state there is a corporeal correlate, and for every bodily operation there is a mental or neural accompaniment; the association of ideas is the mental side of the association of nerve vibrations aroused by their contiguity or succession in past experience. Hartley’s physiological picture was, of course, highly simplified, and never touched the mystery of consciousness; but it shared in reconciling a small minority of Englishmen to the mortality of their minds.

  Another clergyman, Étienne Bonnot de Condillac, approached the problems of mind from a purely psychological side. Born at Grenoble (1714), he was educated at a Jesuit seminary in Paris, and was ordained a priest. Admitted to the salons of Mme. de Tencin and Mme. Geoffrin, he met Rousseau and Diderot, lost religious ardor, abandoned all sacerdotal functions, and gave himself to the game of ideas. He studied the historic systems of philosophy, and rejected them in a Traité des systèmes (1749), which voiced the spirit of the philosophes: all these proud structures of co-ordinated half-truths are fanciful proliferations from our fragmentary knowledge of the universe; it is better to examine a part of experience inductively than to reason deductively about the whole.

  In an Essai sur l’origine des connaissances humaines (1746) Condillac had followed Locke’s analysis of mental operations; but in his most successful production, Traité des sensations (1754), he accepted a more radical view—that the “reflection” in which Locke had recognized a second source of ideas is itself only a combination of sensations, which are the sole source of all mental states. An external world exists, for our most basic sense, that of touch, encounters resistance; nevertheless, all that we know is our sensations and the ideas that they generate.

  Condillac illustrated this proposition with a famous comparison. Perhaps he took it from Buffon, but he ascribed it to his late inspiratrice Mlle. Ferrand, who had left him an obliging legacy. He pictured a marble statue “organized internally like ourselves, but animated by a mind shorn of all ideas,”133 possessing only one sense, that of smell, and capable of distinguishing between pleasure and pain. He proposed to show how from the sensations of this statue all forms of thought could be derived. “Judgment, reflection, desires, passions, etc., are merely sensations variously transformed.”134 Attention is born with the first sensation. Judgment comes with the second, which begets comparison with the first. Memory is a past sensation revived by a present sensation or by another memory. Imagination is a memory vividly revived, or a group of memories projected or combined. Desire or aversion is the active memory of a pleasant or disagreeable sensation. Reflection is the alternation of memories and desires. Will is a strong desire accompanied by an assumption that the object is attainable. Personality, the ego, the self, does not exist at the outset; it takes form as the total collection of the individual’s memories and desires.135 In this way, from merely the sense of smell—or from any other one sense-nearly all operations of the mind can be deduced. Add four other senses, and the statue develops a complex mind.

  All this was an interesting tour de force, and it made considerable noise among the intellectuals of Paris. But critics had no difficulty in showing that Condillac’s method was as deductive and hypothetical as anything in the systems of philosophy; that he quite ignored the problem of consciousness; and that he had not explained how the original sensitivity had arisen. A sensitive statue, even if it only smells, is no statue, unless it be that dignitary whom Turgenev described as posing as proudly as if he were his own monument raised by public subscription.

  In 1767 Condillac was appointed tutor to the future Duke of Parma. He spent the next nine years in Italy, and composed for his pupil seventeen volum
es which were published in 1769–73 as Cours d’études, or Course of Studies. These volumes are of a high order, but the two on history deserve a special salute because they included the history of ideas, manners, economic systems, morals, arts, sciences, amusements, roads—altogether a fuller record of “civilization” than Voltaire had given in the Essai sur les moeurs. In 1780, at the request of Prince Ignacy Potocki, Condillac drew up a Logique for the schools of Lithuania; this too was of exceptional excellence. In that year he died.

  His influence survived for a century, appearing as late as 1870 in Taine’s De l’Intelligence. Condillac’s psychology was standard in the educational system established by the National Convention that governed France from 1792 to 1795. Anatomists like Vicq-d’Azyr, chemists like Lavoisier, astronomers like Laplace, biologists like Lamarck, alienists like Pinel, psychologists like Bonnet and Cabanis, acknowledged his lead. Pierre Jean Georges Cabanis, in 1796, described the brain as “a special organ whose particular function it is to produce thought, just as the stomach and the intestines have the special function of carrying on the work of digestion, and the liver that of filtering bile.”136 The philosophes who surrounded Condillac ignored his professions of faith in God, free will, and an immaterial, immortal soul; they claimed that a naturalistic, semimaterialistic, hedonistic philosophy logically followed from his reduction of all knowledge to sensation, and of all motives to pleasure and pain. Rousseau and Helvétius concluded that if the mind of man at birth is mere receptivity, education can mold intelligence and character with little regard to hereditary differences of mental capacity. Here was the psychological ground of many radical political philosophies.

  The reaction against materialistic psychology came in France only after Napoleon had clipped the claws of the Revolution and had signed the Concordat of 1801 with the Church. It came earlier in Germany, where the antisensationist tradition of Leibniz was still strong. Men like Johann Nicolaus Tetens, professor at the University of Rostock, attacked the school of Condillac as mere theoreticians rather than scientists. All this talk of “vibrations” and “nerve fluid” was pure hypothesis; had anyone seen these things? Tetens argued that a scientific psychology would seek direct observation of mental processes; it would make introspection its major instrument, and would thereby build up a psychology on a truly inductive basis. It would soon find that the “laws of association” formulated by Hobbes, Locke, and Hartley do not correspond with our actual experience; that imagination often revives or combines ideas in quite a different order from that in which sensation gave them; and that links in the chain of association sometimes drop out in a very fanciful way. Desire seems to be the immanent reality of an organism, and hardly conforms to mechanical laws. Mind is an active, forming force, not a “blank paper” upon which sensation writes its will.

  So the stage was set for Immanuel Kant.

  X. THE IMPACT OF SCIENCE UPON CIVILIZATION

  If this chapter, however inadequate, has wound itself out to an abnormal length, it is not only because we have recognized the scientists as well as their science as belonging to history, it is also because the evolution of ideas is our basic interest, and because ideas played a role in the eighteenth century next only to the nature of man himself. If the achievements of science in that revolutionary era were not as startling as those of the preceding century from Galileo and Descartes to Newton and Leibniz, they entered more powerfully into almost every phase of European history. Through Voltaire and a hundred lesser exegetes the results of research were spread in the middle and upper classes; the new sciences of chemistry, geology, and zoology joined in the slow but profound impress of expanding knowledge upon the literate mind; and the effects were endless.

  The influence of science, strange to say, was least and last upon technology. Man’s ways of sowing and reaping, mining and manufacturing, building and transporting, had been formed through centuries of trial and error, and traditions and inertia only reluctantly accepted improvements suggested by laboratory experiments; not till the end of this era did science accelerate the Industrial Revolution. Even so, the first stages of that revolution owed a great deal to chemical researches on dyes; the use of chlorine for bleaching textiles was established by Berthollet (1788), and the industrial manufacture of soda and sal ammoniac was introduced by James Hutton and Nicolas Leblanc. The study of gases by Boyle and Mariotte, and of heat by Black, shared in the development of the steam engine—which, however, was due chiefly to mechanics on the scene. As the century proceeded, a closer rapport grew between practical men seeking production and scientists seeking truth; the Académie des Sciences sent investigators into fields, factories, and workshops, and issued twenty volumes of Descriptions des arts et métiers (1761–81). In return the burgeoning industries began to call upon science for data and experiments; so Coulomb reduced to reliable formulas the tension of beams, and the problems of the steam engine stimulated science to new researches in the relation between force and heat. In the nineteenth century these liaisons were to transform the economic and physical world.

  The major impact of science was naturally upon philosophy, for philosophy, which is the quest of wisdom, must build upon science, which is the pursuit of knowledge. At every step science seemed to enlarge the world in complexity and scope, and new perspectives had to be formed. It was no small adjustment that the human mind had to make after discovering that man was not the center of the universe but an atom and moment in the baffling immensities of space and time; that adjustment has not yet been made. By a proud response as old as Copernicus man was almost overcome by the grandeur of his discovery of his littleness; the pride of science obscured the modesty of philosophy; men conceived new utopias in terms of science, and the idea of progress offered a new religion to the modern soul.

  The effect of science upon religion—or rather upon Christianity—seemed lethal. Doubtless men would continue to form or favor conceptions of the world that would give hope and consolation, meaning and dignity, to harassed, fleeting lives; but how could the Christian epos of creation, original sin, and divine redemption stand up in a perspective that reduced the earth to a speck among a million stars? What was man that the God of such a universe should be mindful of him? How could the poetry of Genesis survive the explorations of geology? And what of the dozen or more religions in regions now opened up by geography?—were they clearly inferior to Christianity in their doctrines or their moral codes and results? How could the miracles of Christ, not to mention those widely ascribed to saints and Satan, be reconciled with the apparent reign of universal law? How could the soul or mind of man be immortal when it seemed so dependent upon the nerves and other tissues visibly doomed to decay? What must happen to the religion so challenged by a science daily growing in scope, achievements, and prestige? And what must happen to a civilization based upon a moral code based upon that religion?

  * * *

  I. This chapter is especially indebted to A. Wolf’s History of Science, Technology, and Philosophy in the 18th Century.

  II. Now began a century of electrical tricks. Georg Bose, a professor in the University of Leipzig, invited several friends to dinner; secretly he insulated the table, but connected various objects on it with an electricity-producing machine hidden in the next room; when the guests were about to eat he signaled an aide to start the machine; sparks flew out from dishes, viands, flowers. He introduced to the company an attractive young woman whose shoes insulated her from the floor, but whose person had been charged with electricity; he invited the guests to kiss her; the gallants received shocks which, reported the professor, nearly “knocked their teeth out.”18

  III. In one of his early experiments he burned two diamonds to prove that the sole product of their combustion was carbon dioxide. As this was also the only product of completely burned charcoal, Lavoisier in this way proved the chemical identity of charcoal and diamonds as forms of pure carbon.

  IV. The name Herschel is typically Jewish, and the astronomer’s first biogra
pher, E. S. Holden, thought that the father, who was named Isaac, was Jewish. The evidence is inconclusive. The boy received Christian baptism at an early age. Cf. The Jewish Encyclopedia, VI, 362d, and Cecil Roth, The Jewish Contributions to Civilization, 189.

  V. Halley’s comet is expected again in 1986.

  VI. “Even in the classical [Newtonian] mechanics Laplace’s proof of the stability of the solar system is no longer considered conclusive.… No rigorous answer has been given.”—Florian Cajori in notes to Newton’s Mathematical Principles of Natural Philosophy, p. 678.

  VII. Astronomic latitude is the angular distance between the equator and the plumb-line direction of gravity at any given place. The meridian of a place is the great circle that passes directly over it from pole to pole.

  VIII. “Just as, in civil history, we examine titles, study coins and medallions, decipher ancient inscriptions, to determine the epochs of human revolutions and fix dates of events in the history of society, even so, in natural history, we must exhume the archives of the world, draw from the bowels of the earth old monuments, collect their remains, and gather into a body of evidence all the indications of physical change that can enable us to go back to the different ages of nature. This is the sole means of fixing some points in the immensity of space, and of placing a certain number of milestones on the eternal route of time. The past is like distance: our view decreases, and would be quite lost if history and chronology had not placed beacons and flares at the obscurest points.”

  IX. Sainte-Beuve phrased this brilliantly: “‘Where were you,’ said God to Job, ‘when I laid the foundations of the earth?’ M. de Buffon seems to say to us, without excitement, ‘I was there.’”75