In truth, the aim of an encyclopedia is to collect all the knowledge scattered over the face of the earth, to present its general outlines and structure to the men with whom we live, and to transmit this to those who will come after us, so that the work of past centuries may be useful to the following centuries, that our children, by becoming more educated, may at the same time become more virtuous and happier, and that we may not die without having deserved well of the human race.... I have said that it could only belong to a philosophical age to attempt an encyclopedia; and I have said this because such a work constantly demands more intellectual daring than is commonly found. All things must be examined, debated, investigated without exception and without regard for anyone's feelings.... We must run roughshod over all these ancient puerilities, overturn the barriers that reason never erected, give back to the arts and sciences the liberty that is so precious to them.... We have for quite some time needed a reasoning age when men would no longer seek the rules in classical authors but in nature.... Fanaticism... is blind and passionate zeal born of superstitious opinions, causing people to commit ridiculous, unjust, and cruel actions, not only without any shame or remorse, but even with a kind of joy and comfort. Fanaticism, therefore, is only superstition put into practice.... Fanaticism has done much more harm to the world than impiety. What do impious people claim? To free themselves of a yoke, while fanatics want to extend their chains over the earth. History... On the usefulness of history. The advantage consists of the comparison that a statesman or a citizen can make of foreign laws, morals, and customs with those of his country. This is what stimulates modern nations to surpass one another in the arts, in commerce, and in agriculture. The great mistakes of the past are useful in all areas. We cannot describe too often the crimes and misfortunes caused by absurd quarrels. It is certain that by refreshing our memory of these quarrels, we prevent a repetition of them.... Intolerance... Any method that would tend to stir up men, to arm nations, and to soak the earth with blood is impious. It is impious to want to impose laws upon man's conscience: this is a universal rule of conduct. People must be enlightened and not constrained.... What did Christ recommend to his disciples when he sent them among the Gentiles? Was it to kill or to die? Was it persecute or to suffer?... Peace... War is the fruit of man's depravity; it is a convulsive and violent sickness of the body politic... If reason governed men and had influence over the heads of nations that deserves, we would never see them inconsiderately surrender themselves to the fury of war; they would not show that ferocity that characterizes wild beasts.... Political Authority... No man has received from nature the right to command others. Liberty is a gift from heaven, and each individual of the same species has the right to enjoy is as soon as he enjoys the use of reason.... The prince owes to his very subjects the authority that he has over them; and this authority is limited by the laws of nature and the state. The laws of nature and the state are the conditions under which they have submitted or are supposed to have submitted to its government.... Moreover, the government, although hereditary in a family and placed in the hands of one person, is not private property, but public property that consequently can never be taken from the people, to whom it belongs.... It is not the state that belongs to the prince, it is the prince who belongs to the state: but it does not rest with the prince to govern the state, because the state has chosen him for that purpose: he has bound himself to the people and the administration of affairs, and they in their turn are bound to obey him according to the laws.... The Slave Trade... is the buying of unfortunate Negroes by Europeans on the coast of Africa to use as slaves in their colonies. This buying of Negroes, to reduce them to slavery, is one business that violates religion, morality, natural laws, and the rights of all human nature. If commerce of this kind can be justified by a moral principle, there is no crime, however atrocious it may be, that cannot be made legitimate. Kings, princes, and magistrates are not the proprietors of their subjects: they do not, therefore, have the right to dispose of their liberty and to sell them as slaves. On the other hand, no man has the right to buy them or make himself their master. Men and their liberty are not objects of commerce; they cannot be neither sold nor bought nor paid for at any price.... There is not, therefore, a single one of these unfortunate people regarded only as slaves who does not have the right to be declared free, since he has never lost his freedom, which he could not lose and which his prince, his father, and any person whatsoever in the world had not the power to dispose of. Consequently the sale that has been completed is invalid in itself. This Negro does not divest himself and can never divest himself of his natural right; he carries it everywhere with him, and he can demand everywhere that he be allowed to enjoy it.