It is false that the sciences have always been prejudicial to mankind. When they were so, the evil was inevitable. The multiplication of the human species on the face of the earth introduced war, the rudiments of arts, and the first laws, which were temporary compacts, arising from necessity, and perishing with it. This was the first philosophy, and its few elements were just, as indolence and want of sagacity in the early inhabitants of the world preserved them from error.
But necessities increasing with the number of mankind, stronger and more lasting impressions were necessary to prevent their frequent relapses into a state of barbarity, which became every day more fatal. The first religious errors, which peopled the earth with false divinities, and created a world of invisible beings to govern the visible creation, were of the utmost service to mankind. The greatest benefactors to humanity were those who dared to deceive, and lead pliant ignorance to the foot of the altar. By presenting to the minds of the vulgar things out of the reach of their senses, which fled as they pursued, and always eluded their grasp which as, they never comprehended, they never despised, their different passions were united, and attached to a single object. This was the first transition of all nations from their savage state. Such was the necessary, and perhaps the only bond of all societies at their first formation. I speak not of the chosen people of God, to whom the most extraordinary miracles and the most signal favours supplied the place of human policy. But as it is the nature of error to subdivide itself ad infinitum, so the pretended knowledge which sprung from it, transformed mankind into a blind fanatic multitude, jarring and destroying each other in the labyrinth in which they were inclosed: hence it is not wonderful that some sensible and philosophic minds should regret the ancient state of barbarity. This was the first epoch, in which knowledge, or rather opinions, were fatal.
The second may be found in the difficult and terrible passage from error to truth, from darkness to light. The violent shock between a mass of errors useful to the few and powerful, and the truths so important to the many and the weak, with the fermentation of passions excited on that occasion, were productive of infinite evils to unhappy mortals. In the study of history, whose principal periods, after certain intervals, much resemble each other, we frequently find, in the necessary passage from the obscurity of ignorance to the light of philosophy, and from tyranny to liberty, its natural consequence, one generation sacrificed to the happiness of the next. But when this flame is extinguished, and the world delivered from its evils, truth, after a very slow progress, sits down with monarchs on the throne, and is worshipped in the assemblies of nations. Shall we then believe, that light diffused among the people is more destructive than darkness, and that the knowledge of the relation of things can ever be fatal to mankind?
Ignorance may indeed be less fatal than a small degree of knowledge, because this adds to the evils of ignorance, the inevitable errors of a confined view of things on this side the bounds of truth; but a man of enlightened understanding, appointed guardian of the laws, is the greatest blessing that a sovereign can bestow on a nation. Such a man is accustomed to behold truth, and not to fear it; unacquainted with the greatest part of those imaginary and insatiable necessities which so often put virtue to the proof, and accustomed to contemplate mankind from the most elevated point of view, he considers the nation as his family, and his fellow-citizens as brothers; the distance between the great and the vulgar appears to him the less as the number of mankind he has in view is greater.
The philosopher has necessities and interests unknown to the vulgar, and the chief of these is not to belie in public the principles he taught in obscurity, and the habit of loving virtue for its own sake. A few such philosophers would constitute the happiness of a nation; which however would be but of short duration, unless by good laws the number were so increased as to lessen the probability of an improper choice.