It is asked what motives has an atheist for doing right.
He can have the motive of pleasing himself and his fellow-creatures; of living happily and tranquilly; of making himself loved and respected by men, whose existence and whose dispositions are better known than those of a being impossible to understand. Can he who fears not the Gods, fear anything? He can fear men, their contempt, their disrespect, and the punishments which the laws inflict; finally, he can fear himself; he can be afraid of the remorse that all those experience whose conscience reproaches them for having deserved the hatred of their fellow-beings. Conscience is the inward testimony which we render to ourselves for having acted in such a manner as to deserve the esteem or the censure of those with whom we associate. This conscience is based upon the knowledge which we have of men, and of the sentiments which our actions must awaken in them. A religious person’s conscience persuades him that he has pleased or displeased his God, of whom he has no idea, and whose obscure and doubtful intentions are explained to him only by suspicious men, who know no more of the essence of Divinity than he does, and who do not agree upon what can please or displease God. In a word, the conscience of a credulous man is guided by men whose own conscience is in error, or whose interest extinguishes intelligence.
Can an atheist have conscience? What are his motives for abstaining from secret vices and crimes of which other men are ignorant, and which are beyond the reach of laws? He can be assured by constant experience that there is no vice which, in the nature of things, does not bring its own punishment. If he wishes to preserve himself, he will avoid all those excesses which can be injurious to his health; he would not desire to live and linger, thus becoming a burden to himself and others. In regard to secret crimes, he would avoid them through fear of being ashamed of himself, from whom he can not hide. If he has reason, he will know the price of the esteem that an honest man should have for himself. He will know, besides, that unexpected circumstances can unveil to the eyes of others the conduct which he feels interested in concealing. The other world gives no motive for doing well to him who finds no motive for it here.
When I read Meslier, I am often reminded of arguments that Christopher Hitchens used to make; it makes me wonder whether Hitch read Meslier or came up with them on his own or from elsewhere. If one had a good enough memory and didn’t mind simply lifting someone else’s work, they could be a Famous Atheist if they learned all of Meslier and recited it at the faithful, in a sort of atheistic Gish Gallop.
Personally, I don’t like the question of “conscience” because I don’t think it is “a thing” other than a set of learned behaviors. We don’t steal because we have been taught not to steal. Religion, to me, other than being a mechanism for social control, fails to have a purpose other than to answer the question “why?” – it’s a bullshit answer, of course, but it’s an answer for some, anyway.
I like the idea that we learn our ideas of “right” and “wrong” from society; that that’s what society is and does – it offers some hope that humankind could learn a society in which sharing and caring were “right” and endless greed was recognized as the fail-move that it is.