“There is no method of reasoning more common, and yet none more blameable, than, in philosophical disputes, to endeavour the refutation of any hypothesis, by a pretence of its dangerous consequences to religion and morality. When any opinion leads to absurdities, it is certainly false; but it is not certain that an opinion is false, because it is of danger-ous consequence. Such topics, therefore, ought entirely to be forborne; as serving nothing to the discovery of truth, but only to make the personof an antagonist odious.”

“When principles are so absurd and so destructive of human society, it may safely be averred, that the more sincere and the more disinterested they are, they only become the more ridiculous and the more odious.”

“the fact that different cultures have different practices no more refutes [moral] objectivism than the fact that water flows in different directions in different places refutes the law of gravity”

“[T]he Old Testament, [...] if considered as a general rule of conduct, would lead to consequences destructive of all principles of humanity and morality.”

“No conclusion can be more agreable to scepticism than such as make discoveries concerning the weakness and narrow limites of human reason and capacity”

“I cannot forbear adding to these reasonings an observation, which may, perhaps, be found of some importance. In every system of morality, which I have hitherto met with, I have always remark’d, that the author proceeds for some time in the ordinary way of reasoning, and establishes the being of a God, or makes observations concerning human affairs; when of a sudden I am surpriz’d to find, that instead of the usual copulations of propositions, is, and is not, I meet with no proposition that is not connected with an ought, or an ought not. This change is imperceptible; but is, however, of the last consequence.”

“Generally speaking, the errors in religion are dangerous; those in philosophy only ridiculous.”