The fundamental idea of Condorcet's Sketch is that of the continual progress of mankind toward perfection. He was a man of the Enlightenment, an advocate of economic freedom, religious toleration and educational reform. A Condorcet biography is available (MacTutor).
* * * * *
The aim of the work that I have undertaken, and its results will be to show by appeal to reason and fact that nature has set no term to the perfection of human faculties; that the perfectibility of man is truly indefinite; and that the progress of this perfectibility, from now on words independent of any power that might wish to halt it, has no other limits than the duration of the globe upon which nature has cast us. This progress will doubtless vary in speed, but it will never be reversed as long as the earth occupies its present place in the system of the universe, and as long as the general laws of the system produce neither a general cataclysm nor such changes as will deprive the human race of its present faculties and its present resources. . . .
It will be necessary to indicate by what stages what must appear to us today a fantastic hope ought in time to become possible, and even likely; to show why, in spite of the transitory successes of prejudice and the support that it receives from the corruption of governments or peoples, truth alone will obtain a lasting victory; we shall demonstrate how nature has joined together indissolubly the progress of knowledge and that of liberty, virtue and respect for the natural rights of man. . . .
After long periods of error, after being led astray by fake were incomplete theories, publicists have at last discovered the true rights of man and how they can all be deduced from the single truth, that man is a sentient being, capable of reasoning and of acquiring moral ideas. . . .
At last man could proclaim aloud his right, which for so long had been ignored, to submit all opinions to his own reason and to use in the search for truth the only instruments for its recognition that he has been given. Every man learnt with a sort of pride that nature had not forever condemned him to base his beliefs on the opinions of others; the superstitions of antiquity and the basement of reason before the [rapture] of supernatural religion disappeared from society as from philosophy.
Thus an understanding of the natural rights of man, the belief that these rights are inalienable and [cannot be forfeited], a strongly expressed desire for liberty of thought and letters, of trade and industry, and for the alleviation of the people's suffering, for the [elimination] of all penal laws against religious dissenters and the abolition of torture and barbarous punishments, the desire for a milder system of criminal legislation and jurisprudence which should give complete security to the innocent, and for a simpler civil code, more in conformance with reason and nature, indifference in all matters of religion which now were relegated to the status of superstitions and political [deception], a hatred of hypocrisy and fanaticism, a contempt for prejudice, zeal for the propagation of enlightenment, all these principles, gradually filtering down from philosophical works to every class of society whose education went beyond the catechism and the alphabet, became the common faith . . . [of enlightened people]. In some countries these principles formed a public opinion sufficiently widespread for even the mass of the people to show a willingness to be guided by and to obey it. . . .
Force or persuasion on the part of governments, priestly intolerance, and even national prejudices, had all lost their deadly power to smother the voice of truth, and nothing could now protect the enemies of reason for the oppressors of freedom from a sentence to which the whole of Europe would soon subscribe. . . .
Our hopes for the future condition of the human race can be subsumed under three important heads: the abolition of inequality between nations, the progress of equality within each nation, and the true perfection of mankind. Will all nations one day attain that state of civilization which the most enlightened, the freest and the least burdened by prejudices, such as the French and the Anglo-Americans [by virtue of their revolutions], have attained already? Will the vast gulf that separates these peoples from the slavery of nations under the rule of monarchs, from the barbarism of African tribes, from the ignorance of savages, little by little disappear? . . .
Is the human race to better itself, either by discoveries and sciences and the arts, and so in the means to individual welfare and general prosperity; or by progress in the principles of conduct or practical morality; or by a true perfection of the intellectual, moral, or physical faculties of man, an improvement which may result from a perfection either of the instruments used to heighten the intensity of these faculties and to direct their use or of the natural constitution of man?
In answering these three questions we shall find in the experience of the past, in the observation of the progress at the sciences and civilization have already made, in the analysis of the progress of the human mind and of the development of its faculties, the strongest reasons for believing that nature has set no limit to the realization of our hopes. . . .
The time will therefore come when the sun will shine only on free man who know no other master but their reason; when tyrants and slaves, priests and their stupid or hypocritical instruments will exist only in works of history and on the stage; and when we shall think of them only to pity their victims and their dupes; to maintain ourselves in a state of vigilance by thinking on their excesses; and to learn how to recognize and so to destroy, by force of reason, the first seeds of tyranny and superstition, should they ever dare to reappear among us.
[Source: Marie Jean Antoine de Condorect, Sketch for a Historical Picture of the Progress of the Human Mind, trans. June Barraclough (London: Weidenfeld & Nicolson, 1955), pp. 4-5, 9-10, 128, 136, 140-142, 173-175.]