The happiness which man derives from them is the invariable, the necessary standard of his sentiments, for the beings of his species; for the objects he desires; for the opinions he embrases; for those actions on which he decides. He is the dupe of his prejudices every time he ceases to avail himself of this standard to regulate his judgment. He will never run the risk of deceiving himself, when he shall examine strictly what is the real utility resulting to his species from the religion, from the superstition, from the laws, from the institutions, from the inventions, from the various actions of all mankind.
A superficial view may sometimes seduce him; but experience, aided by reflection, will reconduct him to reason, which is incapable of deceiving him. This teaches him that pleasure is a momentary happiness, which frequently becomes an evil; that evil is a fleeting trouble that frequently becomes a good: it makes him understand the true nature of objects, enables him to foresee the effects he may expect; it makes him distinguish those desires to which his welfare permits him to lend himself, from those to whose seduction he ought to make resistance. In short, it will always convince him that the true interest of intelligent beings, who love happiness, who desire to render their own existence felicitous, demands that they should root out all those phantoms, abolish all those chimerical ideas, destroy all those prejudices, which by traducing virtue, obstruct their felicity in this world.
If he consults experience, he will perceive that it is in illusions, in false opinions, rendered sacred by time, that he ought to search out the source of that multitude of evils which almost every where overwhelms mankind. From ignorance of natural causes, man has created imaginary causes; not knowing to what cause to attribute thunder, he ascribed it to an imaginary being whom he called JUPITER; imposture availing itself of this disposition, rendered these causes terrible to him; these fatal ideas haunted him without rendering him better; made him tremble without either benefit to himself or to others; filled his mind with chimeras that opposed themselves to the progress of his reason; that prevented him from really seeking after his happiness. His vain fears rendered him the slave of those who deceived him, under pretence of consulting his welfare; he committed evil, because they persuaded him his gods demanded sacrifices; he lived in misfortune, because they made him believe these gods condemned him to be miserable; the slave of beings, to which his own imagination had given birth, he never dared to disentangle himself from his chains; the artful ministers of these divinities gave him to understand that stupidity, the renunciation of reason, sloth of mind, abjection of soul, were the sure means of obtaining eternal felicity.
