The Highs and Lows of Enlightenment

From the time when the genius of Descartes impressed on the minds of men that general impulse, which is the first principle of a revolution in the destiny of the human species, to the happy period of entire social liberty, in which man has not been able to regain his natural independence till after having passed through a long series of ages of misfortune and slavery, the view of the progress of mathematical and physical science presents to us an immense horizon, of which it is necessary to distribute and assort the several parts, whether we may be desirous of fully comprehending the whole, on of observing their mutual relations.

The application of algebra to geometry not only became the fruitful source of discoveries in both sciences, but they prove, from this striking example, how much the method of computation of magnitudes in general may be extended to all questions, the object of which consists in measure and extension. Descartes first announced the truth, that they would be employed with equal success hereafter upon all objects susceptible of precise valuation; and this great discovery, by shewing for the first time the ultimate purpose of these sciences, that is to say, the strict calculation of every species of truth, afforded the hope of attaining this point, at the same time that it exhibited the means.

This discovery was soon succeeded by that of a new method of computing, which teaches us to find the ratios of the successive increments or decrements of a variable quantity, or to deduce the quantity itself when this ratio is given; whether the increments be supposed of finite magnitude, or their ratio be sought for the instant only of their vanishment; a method which, being extended to all the combinations of variable magnitudes, and to all the hypotheses of their variations, leads to a determination, with regard to all things precisely measurable, of the ratios of their elements, or of the things themselves, from the knowledge of those proportions which they mutually have, provided the ratios of their elements only be given.

We are indebted to Newton and Leibnitz for the invention of these methods; but the labours of the geometers of the preceding age prepared the way for this discovery. The progress of these sciences, which has been uninterrupted for more than a century, is the work, and establishes the reputation, of a number of men of genius. They present to the eyes of the philosopher, who is able to observe them, even though he may not follow their steps, a striking monument of the force of the human mind.

When we explain the formation and principles of algebraic language, which alone is accurate and truly analytic; the nature of the technical processes of this science; and the comparison of these processes with the natural operations of the human mind, we may prove that, if this method be not itself a peculiar instrument in the science of quantity, it certainly includes the principles of an universal instrument applicable to all possible combinations of ideas.

Rational mechanics soon became a vast and profound science. The true laws of the collision of bodies, respecting which Descartes was deceived, were at length known.

Huygens discovered the laws of circular motions; and at the same time he gives a method of determining the radius of curvature for every point of a given curve. By uniting both theories, Newton invented the theory of curve-​lined motions, and applied it to those laws according to which Kepler had discovered that the planets describe their elliptical orbits….

Thus we see man has at last become acquainted, for the first time, with one of the physical laws of the universe. Hitherto it stands unparalleled, as does the glory of him who discovered it.

An hundred years of labour and investigation have confirmed this law, to which all the celestial phenomena are subjected, with an accuracy which may be said to be miraculous. Every time in which an apparent deviation has presented itself, the transient uncertainty has soon become a subject of new triumph to the science….

But Newton did more, perhaps, in favour of the progress of the human mind, than merely discovering this general law of nature; he taught men to admit in natural philosophy no other theories but such as are precise, and susceptible of calculation; which give an account not only of the existence of a phenomenon, but its quantity and extent. Nevertheless he was accused of reviving the occult qualities of the ancients, because he had confined himself to refer the general cause of celestial appearances to a simple fact, of which observation proved the incontestable reality; and this accusation is itself a proof how much the methods of the sciences still require to be enlightened by philosophy….

The weight of the air is known and measured: it is known that the transmission of light is not instantancous; its velocity is determined, with the effects which must result from that velocity, as to the apparent position of the celestial bodies; and the decomposition of the solar rays into others of different refrangibility and colour. The rainbow is explained, and the methods of causing its colours to be produced or to disappear are subjected to calculation. Electricity, formerly considered as the property of certain substances only, is now known to be one of the most general phenomena in the universe. The cause of thunder is no longer a secret; Franklin has taught the artist to change its course, and direct it at pleasure. New instruments are employed to measure the variations of weight and humidity in the atmosphere, and the temperature of all bodies. A new science, under the name of meteorology, teaches us to know, and sometimes to foretell, the atmospheric appearances of which it will hereafter disclose to us the unknown laws….

Natural philosophy has been obliged to combat with the prejudices of the schools, and the attraction of general hypotheses, so seducing to indolence. Other obstacles retarded the progress of chemistry. It was imagined that this science ought to afford the secret of making gold, and that of rendering man immortal.

The effect of great interests, is to render man superstitious. It was not supposed that such promises, which flatter the two strongest passions of vulgar minds, and besides rouse that of acquiring glory, could be accomplished by ordinary means; and every thing which credulity or folly could ever invent of extravagance, seemed to unite in the minds of chemists.

But these chimeras gradually gave place to the mechanical philosophy of Descartes, which in its turn gave place to a chemistry truly experimental. The observation of those facts which accompany the mutual composition and decomposition of bodies, the research into the laws of these operations, with the analysis of substances into elements of greater simplicity, acquire a degree of precision and strictness ever increasing.

But to these advances of chemistry we must add others, which embrace the whole system of the science, and rather by extending the methods than immediately increasing the mass of truths, foretell and prepare a revolution of the happiest kind….

Men who long had possessed no other knowledge than that of explaining by superstitious or philosophical reveries the formation of the earth, before they endeavoured to become acquainted with its parts, have at last perceived the necessity of studying with the most scrupulous attention the surface of the ground, the internal parts of the earth into which necessity has urged men to penetrate, the substances there found, their fortuitous or regular distribution, and the disposition of the masses they have formed by their union. They have learned to ascertain the effects of the slow and long continued action of the waters of the sea, of rivers, and the effect of volcanic fires; to distinguish those parts of the surface and exterior crust of the globe, of which the inequalities, disposition, and frequently the materials themselves, are the work of these agents; from the other portion of the surface, formed for the most part of heterogeneous substances, bearing the marks of more ancient revolutions by agents with which we are yet acquainted.

Minerals, vegetables, and animals are divided into various species, of which the individuals differ by insensible variations scarcely constant, or produced by causes purely local. Many of these species resemble each other by a greater or less number of common qualities, which serve to establish successive divisions regularly more and more extended. Naturalists have invented methods of classing the objects of science from determinate characters easily ascertained, the only means of avoiding confusion in the midst of this numberless multitude of individuals. These methods are, indeed, a real language, wherein each object is denoted by some of its most constant qualities, which, when known, are applicable to the discovery of the name which the article may bear in common language. These general languages, when well composed, likewise indicate, in each class of natural objects, the truly essential qualities which by their union cause a more or less perfect resemblance in the rest of their properties.

We have formerly seen the effects of that pride which magnifies in the eyes of men the objects of an exclusive study, and knowledge painfully acquired, which attaches to these methods an exaggerated degree of importance, and mistakes for science itself that which is nothing more than the dictionary and grammar of its real language. And so likewise, by a contrary excess, we have seen philosophers falsely degrade these same methods, and confound them with arbitrary nomenclatures, as futile and laborious compilations….

The physical man is himself the object of a separate science, anatomy, which, in its general acceptation, includes physiology. This science, which a superstitious respect for the dead had retarded, has taken advantage of the general disappearance of prejudice, and has happily opposed the interest of the preservation of man, which has secured it the patronage of men of eminence. Its progress has been such, that it seems in some sort to be at a stand, in the expectation of more perfect instruments and new methods. It is nearly reduced to seek in the comparative anatomy of the parts of animals and man, in the organs common to the different species, and the manner in which they exercise similar functions, those truths which the direct observation of the human frame appears to refuse. Almost every thing which the eye of the observer, assisted by the microscope, has been able to discover, is already ascertained. Anatomy appears to stand in need of experiments, so useful to the progress of other sciences; but the nature of its object deprives it of this means, so evidently necessary to its perfection….

We may shew the influence which the progress of mechanics, of astronomy, of optics, and of the art of measuring time, has exercised on the art of constructing, moving, and directing vessels at sea. We may shew how greatly an increase of the number of observers, and a greater degree of accuracy in the astronomical determinations of positions, and in topographical methods, have at last produced an acquaintance with the surface of the globe, of which so little was known at the end of the last century.

How greatly the mechanic arts, properly so called, have given perfection to the processes of art in constructing instruments and machines in the practice of trade, and these last have no less added force to rational mechanism and philosophy. These arts are also greatly indebted to the employment of first movers already known, with less of expence and loss, as well as to the invention of new principles of motion.

We have beheld architecture extend its researches into the science of equilibriums and the theory of fluids, for the means of giving the most commodious and least expensive form to arches, without fear of altering their solidity; and to oppose against the effort of water a resistance computed with greater certainty; to direct the course of that fluid, and to employ it in canals with greater skill and success….

In the mean time, chemistry, botany, and natural history, have very much enlightened the economical arts, and the culture of vegetables destined to supply our wants; such as the art of supporting, multiplying, and preserving domestic animals; the bringing their races to perfection, and meliorating their products; the art of preparing and preserving the productions of the earth, or those articles which are of animal product.

Surgery and pharmacy have become almost new arts, from the period when anatomy and chemistry have offered them more enlightened and more certain direction.

The art of medicine, for in its practice it must be considered as an art, is by this means delivered at least of its false theories, its pedantic jargon, its destructive course of practice, and the servile submission to the authority of men, or the doctrine of colleges; it is taught to depend only on experience. The means of this art have become multiplied, and their combination and application better known; and though it may be admitted that in some parts its progress is merely of a negative kind, that is to say, in the destruction of dangerous practices and hurtful prejudices, yet the new methods of studying chemical medicine, and of combining observations, give us reason to expect more real and certain advances….

These observations will lead us to one general truth, that in all the arts the results of theory are necessarily modified in practice; that certain sources of inaccuracy exist, which are really inevitable, of which our aim should be to render the effect insensible, without indulging the chimerical hope of removing them; that a great number of data relative to our wants, our means, our time, and our expences which are necessarily overlooked in the theory, must enter into the relative problem of immediate and real practice; and that, lastly by introducing these requisites with that skill which truly constitutes the genius of the practical man, we may at the same time go beyond the narrow limits wherein prejudice against theory threatens to detain the arts, and prevent those errors into which an improper use of theory might lead us.

Those sciences which are remote from each other, cannot be extended without bringing them nearer, and forming points of contact between them….

But we have yet exposed no more than a small portion of the advantages which have been received, or may be expected, from these applications.

How greatly have inquiries into the duration of human life, and the influence in this respect of sex, temperature, climate, profession, government, and habitudes of life; on the mortality which results from different diseases; the changes which population experiences; the extent of the action of different causes which produce these changes; the manner of its distribution, in each country, according to the age, sex, and occupation:—how greatly useful have these researches been to the physical knowledge of man, to medicine, and to public economy.

How extensively have computations of this nature been applied for the establishment of annuities, tontines, accumulating funds, benefit societies, and chambers of assurance of every kind.

Is not the application of numbers also necessary to that part of the public economy which includes the theory of public measures, of coin, of banks and financial operations, and lastly, that of taxation, as established by law, and its real distribution, which so frequently differs, in its effects on all the parts of the social system.

What a number of important questions in this same science are there, which could not have been properly resolved without the knowledge acquired in natural history, agriculture, and the philosophy of vegetables, which influence the mechanical or chymical arts.

In a word, such has been the general progress of the sciences, that it may be said there is not one which can be considered as to the whole extent of its principles and detail, without our being obliged to borrow the assistance of all the others….

If we confine ourselves to exhibit the advantages deduced from the sciences in their immediate use or application to the arts, whether for the welfare of individuals or the prosperity of nations, we shall have shewn only a small part of the benefits they afford. The most important perhaps is, that prejudice has been destroyed, and the human understanding in some sort rectified; after having been forced into a wrong direction by absurd objects of belief, transmitted from generation to generation, taught at the misjudging period of infancy, and enforced with the terrors of superstition and the dread of tyranny.

All the errors in politics and in morals are founded upon philosophical mistakes, which, themselves, are connected with physical errors. There does not exist any religious system, or supernatural extravagance, which is not founded on an ignorance of the laws of nature. The inventors and defenders of these absurdities could not foresee the successive progress of the human mind. Being persuaded that the men of their time knew every thing, they would ever know, and would always believe that in which they then had fixed their faith; they confidently built their reveries upon the general opinions of their own country and their own age.

The progress of natural knowledge is yet more destructive of these errors, because it frequently destroys them without seeming to attack them, by attaching to those who obstinately defend them the degrading ridicule of ignorance….

The picture of the fine arts offers to our view results of no less brilliancy. Music is become, in a certain respect, a new art; while the science of combination, and the application of numbers to the vibrations of sonorous bodies, and the oscillations of the air, have enlightened its theory. The arts of design, which formerly passed from Italy to Flanders, Spain and France, elevated themselves in this last country to the same degree that Italy carried them in the preceding epocha; where they have been supported with more reputation than in Italy itself. The art of our painters is that of Raphael and Carrachi. All the means of the art being preserved in the schools, are so far from being lost, that they have become more extended. Nevertheless, it must be admitted, that too long a time has elapsed without producing a genius which may be compared to them, to admit of this long sterility being attributed to chance. It is not because the means of art are exhausted that great success is really become difficult; it is not that nature has refused us organs equally perfect with those of the Italians of the sixth age; it is merely to the changes of politics and manners that we ought to attribute, not the decay of the art, but the mediocrity of its productions.

Literary productions (cultivated in Italy with less success but without having degenerated) have made such progress in the French language, as has acquired it the honour of becoming, in some sort, the universal language of Europe.

The tragic art, in the hands of Corneille, Racine, and Voltaire, has been raised, by successive progress, to a perfection before unknown. The comic art is indebted to Moliere for having speedily arrived to an elevation not yet attained by any other people.

In England, from the commencement of the same epoch, and in a still later time in Germany, language has been rendered more perfect. The art of poetry, as well as that of prose writing, have been subjected, though with less docility than in France, to the universal rules of reason and nature, which ought to direct them. These rules are equally true for all languages and all people, though the number of men has hitherto been few who have succeeded in arriving at the knowledge of them, and rising to the just and pure taste which results from that knowledge….

We may shew how far the art of printing, by multiplying and disseminating even those works which are designed to be publicly read or recited, transmit them to a number of readers incomparably greater than that of the auditors. We may shew how most of the important decisions by numerous assemblies, having been determined from the previous instruction their members had received by writing, there must have resulted in the art of persuasion among the ancients and among the moderns, differences in the rules, analogous to the effect intended to be produced and the means employed; and how, lastly, in the different species of knowledge, even with the ancients, certain works were for perusal only—such as those of history or philosophy. The facility which the invention of printing affords, to enter into a more extensive detail and more accurate developement, must have likewise influenced the same rules.

The progress of philosophy and the sciences have extended and favoured those of letters, and these in their turn have served to render the study of the sciences more easy, and philosophy itself more popular. They have lent mutual assistance to each other, in spite of the efforts of ignorance and folly to disunite and render them inimical. Erudition, which a respect for human authority and ancient things seemed to have destined to support the cause of hurtful prejudices; this erudition has, nevertheless, assisted in destroying them, because the sciences and philosophy have enlightened it with a more legitimate criticism. It already knew the method of weighing authorities, and comparing them with each other, but it has at length submitted them to the tribunal of reason; it had rejected the prodigies, absurd tales, and facts contrary to probability; but, by attacking the testimony upon which they were supported, men have learned to reject them, in spite of the force of these witnesses, that they might give way to that evidence which the physical or moral improbability of extraordinary facts might carry with them.

Hence it is seen that all the intellectual occupations of men, however differing in their object, their method, or the qualities of mind which they require, have concurred in the progress of human reason. It is the same with the entire system of the labours of men as with a well-​composed work; of which the parts, though methodically distinct, must, nevertheless, be closely connected to form one single whole, and tend to one single object.

While we thus take a general view of the human species, we may prove that the discovery of true methods in all the sciences; the extent of the theories they include; their application to all the objects of nature, and all the wants of man; the lines of communication established between them; the great number of those who cultivate them; and, lastly, the multiplication of printing presses, are sufficient to assure us, that none of them will hereafter descend below the point to which it has been carried. We may shew that the principles of philosophy, the maxims of liberty, the knowledge of the true rights of man, and his real interest, are spread over too many nations, and in each of those nations direct the opinions of too great a number of enlightened men, for them ever to fall again into oblivion….

But if it be true, as every prospect assures us, that the human race shall not again relapse into its ancient barbarity; if every thing ought to assure us against that pusillanimous and corrupt system which condemns man to eternal oscillations between truth and falsehood, liberty and servitude, we must, at the same time, perceive that the light of information is spread over a small part only of our globe; and the number of those who possess real instruction, seems to vanish in the comparison with the mass of men consigned over to ignorance and prejudice. We behold vast countries groaning under slavery, and presenting nations in one place, degraded by the vices of civilization, so corrupt as to impede the progress of man; and in others, still vegetating in the infancy of its early age. We perceive that the exertions of these last ages have done much for the progress of the human mind, but little for the perfection of the human species; much for the glory of man, somewhat for his liberty, but scarcely any thing yet for his happiness. In a few directions, our eyes are struck with a dazzling light; but thick darkness still covers an immense horizon. The mind of the philosopher reposes with satisfaction upon a small number of objects, but the spectacle of the stupidity, the slavery, the extravagance, and the barbarity of man, afflicts him still more strongly. The friend of humanity cannot receive unmixed pleasure but by abandoning himself to the endearing hope of the future.

Such are the objects which ought to enter into an historical sketch of the progress of the human mind. We may endeavour, while we hold them forward, to shew more especially the influence of this progress upon the opinions and the welfare of the general mass of different nations, at the different epochas of their political existence; to shew what truths they have known, what errors have been destroyed, what virtuous habits contracted, what new developement of their faculties has established a happier proportion between their powers and their wants: And, under an opposite point of view, what may be the prejudices to which they have been enslaved; what religious or political superstitions have been introduced; by what vices, of ignorance or despotism, they have been corrupted; and to what miseries, violence or their own degradation have subjected them.

Hitherto, political history, as well as that of philosophy and the sciences, has been merely the history of a few men. That which forms in truth the human species, the mass of families, which subsist almost entirely upon their labour, has been forgotten; and even among that class of men who, devoted to public professions, act not for themselves but for society; whose occupation it is to instruct, to govern, to defend, and to comfort other men, the chiefs only have fixed the attention of historians….

To this part of the history of the human species, which is the most obscure, the most neglected, and for which facts offer us so few materials, it is that we should more particularly attend in this outline; and whether an account be rendered of a new discovery, an important theory, a new system of laws, or a political revolution, the problem to be determined will consist in ascertaining what effects ought to have arisen from the will of the most numerous portion of each society. This is the true object of philosophy; because all the intermediate effects of these same causes can be considered only as means of acting, at least upon this portion, which truly constitutes the mass of the human race.

It is by arriving at this last link of the chain, that the observation of past events, as well as the knowledge acquired by meditation, become truly useful. It is by arriving at this term, that men learn to appreciate their real titles to reputation, or to enjoy, with a well-​grounded pleasure, the progress of their reason. Hence, alone, it is, that they can judge of the true improvement of the human species….