It was from the spread of reason and science among individual men that the great apostles of the Enlightenment hoped to bring about the ideal society of mankind. And from this spread they hoped for a veritable millennium. From the beginning of the [18th] century onward there rose one increasing paean to progress through education…

All men, of whatever school, believed with all their ardent natures in the perfectibility of the human race. At last mankind held in its own hands the key to its destiny: it could make the future almost what it would. By destroying the foolish errors of the past and returning to a rational cultivation of nature, there were scarcely any limits to human welfare that might not be transcended.

It is difficult for us to realize how recent a thing is this faith in human progress. The ancient world seems to have had no conception of it; Greeks and Romans looked back rather to a Golden Age from which man had degenerated. The Middle Ages, of course, could brook no such thought. The Renaissance, which actually accomplished so much, could not imagine that man could ever rise again to the level of glorious antiquity; its thoughts were all on the past.

Only with the growth of science in the seventeenth century could men dare to cherish such an overweening ambition. To Fontenelle, whose long life stretched from the days of Descartes to those of the Encyclopedia, belongs the chief credit for instilling the eighteenth-century faith in progress. He was a popularizer of Cartesian science, and it was from science and reason that he hoped that Europe would not only equal but far surpass antiquity.

All men, he proclaimed, are of the same stuff; we are like Plato and Homer, and we have a vastly richer store of accumulated experience than they. Men reverence age for its wisdom and experience; it is we moderns who really represent the age of the world, and the ancients who lived in its youth. A scientist to day knows ten times as much as a scientist living under Augustus. So long as men continue to accumulate knowledge, progress will be as inevitable as the growth of a tree; nor is there any reason to look for its cessation.

This opinion may strike us as almost platitudinous, but to Fontenelle’s contemporaries it seemed the rankest of heresies. He found himself involved in a furious battle, and all France took sides in the conflict between the Ancients and the Moderns… But of the ultimate outcome there could be no question; all the scientists, from Descartes down, despised the ancients and carried the day for the faith in progress…

It remained for Condorcet to sum up the hopes and the confidence of the whole age. Mathematician, statesman, educator, Revolutionist, Condorcet’s life stands as the symbol of the very soul of the French Revolution… While in hiding for his life he spent his time composing the most sublimely confident book that has ever been written, the History of the Progress of the Human Spirit... Looking back upon the past, he finds there, in the increasingly rapid growth of knowledge and enlightenment, the platform from which to launch the soul of man into the triumphs of the future…

The result of my work will be to show, by reasoning and by facts, that there is no limit set to the perfecting of the powers of man; that human perfectibility is in reality indefinite; that the progress of this perfectibility, henceforth independent of any power that might wish to stop it, has no other limit than the duration of the globe upon which nature has placed us.

Doubtless this progress can proceed at a pace more or less rapid, but it will never go backward; at least, so long as the earth occupies the same place in the system of the universe, and as the general laws of this system do not produce upon the globe a general destruction, or changes which will no longer permit the human race to preserve itself, to employ the same powers, and to find the same resources.

The principles of the Revolution, that is, of eighteenth-century faith in reason, will spread over the entire earth; liberty and equality, a real economic and social and intellectual equality, will be continually strengthened; peace will reign on earth; “War will come to be considered the greatest of pestilences and the greatest of crimes.” Nay, more; a better organization of knowledge, and an intelligent improvement in the quality of the human organism itself, will lead not only to the disappearance of disease and an indefinite prolongation of human life, but to the actual attainment of the perfect conditions of human well-being.