Paul Henri Thiry d'Holbach, System of Nature

"If a faithful account was rendered of man's ideas upon the Divinity, he would be obliged to acknowledge, that for the most part the word Gods has been used to express the concealed, remote, unknown causes of the effects he witnessed; that he applies this term when the spring of natural, the source of known causes ceases to be visible: as soon as he loses the thread of these causes, or as soon as his mind can no longer follow the chain, he solves the difficulty, terminates his research, by ascribing it to his gods; thus giving a vague definition to an unknown cause, at which either his idleness, or his limited knowledge, obliges him to stop. When, therefore, he ascribes to his gods the production of some phenomenon, the novelty or the extent of which strikes him with wonder, but of which his ignorance precludes him from unravelling the true cause, or which he believes the natural powers with which he is acquainted are inadequate to bring forth; does he, in fact, do any thing more than substitute for the darkness of his own mind, a sound to which he has been accustomed to listen with reverential awe?"