The principles of atheism are not formed for the mass of the people, who are commonly under the tutelage of their priests; they are not calculated for those frivolous capacities, not suited to those dissipated minds, who fill society with their vices, who hourly afford evidence of their own inutility; they will not gratify the ambitious; neither are they adapted to intriguers, nor fitted for those restless beings who find their immediate interest in disturbing the harmony of the social compact: much less are they made for a great number of persons, who, enlightened in other respects, have not sufficient courage to divorce themselves from the received prejudices.

So many causes unite themselves to confirm man in those errors which he draws in with his mother's milk, that every step that removes him from these endeared fallacies, costs him uncommon pain. Those persons who are most enlightened, frequently cling on some side to the general prepossession. By giving up these revered ideas, we feel ourselves, as it were, isolated in society: whenever we stand alone in our opinions, we no longer seem to speak the language of our associates; we are apt to fancy ourselves placed on a barren, desert island, in sight of a populous, fruitful country, which we can never reach: it therefore requires great courage to adopt a mode of thinking that has but few approvers. In those countries where human knowledge has made some progress; where, besides, a certain freedom of thinking is enjoyed, may easily be found a great number of deicolists, theists, or incredulous beings, who, contented with having trampled under foot the grosser prejudices of the illiterate, have not dared to go back to the source--to cite the more subtle systems before the tribunal of reason. If these thinkers did not stop on the road, reflection would quickly prove to them that those systems which they have not the fortitude to examine, are equally injurious to sound ratiocination, fully as revolting to good sense, quite as repugnant to the evidence of experience, as any of those doctrines, mysteries, fables, or superstitious customs, of which they have already acknowledged the futility; they would feel, as we have already proved, that all these things are nothing more than the necessary consequences of those primitive errors which man has indulged for so many ages in succession; that in admitting these errors, they no longer have any rational cause to reject the deductions which the imagination has drawn from them. A little attention would distinctly shew them, that it is precisely these errors that are the true cause of all the evils of society; that those endless disputes, those sanguinary quarrels, to which superstition and the spirit of party every instant give birth, are the inevitable effects of the importance they attach to errors which possess all the means of distraction, that scarcely ever fail to put the mind of man into a state of combustion. In short, nothing is more easy than to convince ourselves that imaginary systems, not reducible to comprehension, which are always painted under terrific aspects, must act upon the imagination in a very lively manner, must sooner or later produce disputes--engender enthusiasm--give birth to fanaticism--end in delirium.

The System of Nature, Volume 2 — Part 198