Philosophical Dictionary, by Voltaire


We understand by system a supposition; for if a system can be proved, it is no longer a system, but a truth. In the meantime, led by habit, we say the celestial system, although we understand by it the real position of the stars.

I once thought that Pythagoras had learned the true celestial system from the Chaldæans; but I think so no longer. In proportion as I grow older, I doubt of all things. Notwithstanding that Newton, Gregory, and Keil honor Pythagoras and the Chaldæans with a knowledge of the system of Copernicus, and that latterly M. Monier is of their opinion, I have the impudence to think otherwise.

One of my reasons is, that if the Chaldæans had been so well informed, so fine and important a discovery would not have been lost, but would have been handed down from age to age, like the admirable discoveries of Archimedes.

Another reason is that it was necessary to be more widely informed than the Chaldæans, in order to be able to contradict the apparent testimony of the senses in regard to the celestial appearances: that it required not only the most refined experimental observation, but the most profound mathematical science; as also the indispensable aid of telescopes, without which it is impossible to discover the phases of Venus, which prove her course around the sun, or to discover the spots in the sun, which demonstrate his motion round his own almost immovable axis. Another reason, not less strong, is that of all those who have attributed this discovery to Pythagoras, no one can positively say how he treated it.

Diogenes Laertius, who lived about nine hundred years after Pythagoras, teaches us, that according to this grand philosopher, the number one was the first principle, and that from two sprang all numbers; that body has four elements — fire, water, air, and earth; that light and darkness, cold and heat, wet and dry, are equally distributed; that we must not eat beans; that the soul is divided into three parts; that Pythagoras had formerly been Atalides, then Euphorbus, afterwards Hermotimus; and, finally, that this great man studied magic very profoundly. Diogenes says not a word concerning the true system of the world, attributed to this Pythagoras; and it must be confessed that it is by no means to an aversion to beans that we owe the calculations which at present demonstrate the motion of the earth and planets generally.

The famous Arian Eusebius, bishop of Cæsarea, in his “Evangelical Preparation,” expresses himself thus: “All the philosophers declare that the earth is in a state of repose; but Philolaus, the peripatetic, thinks that it moves round fire in an oblique circle, like the sun and the moon.” This gibberish has nothing in common with the sublime truths taught by Copernicus, Galileo, Kepler, and above all by Newton.

As to the pretended Aristarchus of Samos, who, it is asserted, developed the discoveries of the Chaldæans in regard to the motion of the earth and other planets, he is so obscure, that Wallace has been obliged to play the commentator from one end of him to the other, in order to render him intelligible.

Finally, it is very much to be doubted whether the book, attributed to this Aristarchus of Samos, really belongs to him. It has been strongly suspected that the enemies of the new philosophy have constructed this forgery in favor of their bad cause. It is not only in respect to old charters that similar forgeries are resorted to. This Aristarchus of Samos is also the more to be suspected, as Plutarch accuses him of bigotry and malevolent hypocrisy, in consequence of being imbued with a direct contrary opinion. The following are the words of Plutarch, in his piece of absurdity entitled “The Round Aspect of the Moon.” Aristarchus the Samian said, “that the Greeks ought to punish Cleanthes of Samos, who suggested that the heavens were immovable, and that it is the earth which travels through the zodiac by turning on its axis.”

They will tell me that even this passage proves that the system of Copernicus was already in the head of Cleanthes and others — of what import is it whether Aristarchus the Samian was of the opinion of Cleanthes, or his accuser, as the Jesuit Skeiner was subsequently Galileo’s? — it equally follows that the true system of the present day was known to the ancients.

I reply, no; but that a very slight part of this system was vaguely surmised by heads better organized than the rest. I further answer that it was never received or taught in the schools, and that it never formed a body of doctrine. Attentively peruse this “Face of the Moon” of Plutarch, and you will find, if you look for it, the doctrine of gravitation; but the true author of a system is he who demonstrates it.

We will not take away from Copernicus the honor of this discovery. Three or four words brought to light in an old author, which exhibit some distant glimpse of his system, ought not to deprive him of the glory of the discovery.

Let us admire the great rule of Kepler, that the revolutions of the planets round the sun are in proportion to the cubes of their distances. Let us still more admire the profundity, the justness, and the invention of the great Newton, who alone discovered the fundamental reasons of these laws unknown to all antiquity, which have opened the eyes of mankind to a new heaven.

Petty compilers are always to be found who dare to become the enemies of their age. They string together passages from Plutarch and Athenæus, to prove that we have no obligations to Newton, to Halley, and to Bradley. They trumpet forth the glory of the ancients, whom they pretend have said everything; and they are so imbecile as to think that they divide the glory by publishing it. They twist an expression of Hippocrates, in order to persuade us that the Greeks were acquainted with the circulation of the blood better than Harvey. Why not also assert that the Greeks were possessed of better muskets and field-pieces; that they threw bomb-shells farther, had better printed books, and much finer engravings? That they excelled in oilpaintings, possessed looking-glasses of crystal, telescopes, microscopes, and thermometers? All this may be found out by men, who assure us that Solomon, who possessed not a single seaport, sent fleets to America, and so forth.

One of the greatest detractors of modern times is a person named Dutens, who finished by compiling a libel, as infamous as insipid, against the philosophers of the present day. This libel is entitled the “Tocsin”; but he had better have called it his clock, as no one came to his aid; and he has only tended to increase the number of the Zoilusses, who, being unable to produce anything themselves, spit their venom upon all who by their productions do honor to their country and benefit mankind.

Last updated Sunday, March 27, 2016 at 12:01