God has never communicated with people except through creation and conscience

But though, speaking for myself, I thus admit the possibility of revelation, I totally disbelieve that the Almighty ever did communicate any thing to man, by any mode of speech, in any language, or by any kind of vision, or appearance, or by any means which our senses are capable of receiving, otherwise than by the universal display of himself in the works of the creation, and by that repugnance we feel in ourselves to bad actions, and disposition to good ones.