the fact that different cultures have different practices no more refutes [moral] objectivism than the fact that water flows in different directions … - David Hume

And any practice, recommended to him, which either serves to no purpose in life, or offers the strongest violence to his natural inclinations; that practice he will the more readily embrace, on account of those very circumstances, which should make him absolutely reject it. It seems the more purely religious, because it proceeds from no mixture of any other motive or consideration. And if, for its sake, he sacrifices much of his ease and quiet, his claim of merit appears still to rise upon him, in proportion to the zeal and devotion which he discovers. In restoring a loan, or paying a debt, his divinity is nowise beholden to him; because these acts of justice are what he was bound to perform, and what many would have performed, were there no god in the universe. But if he fast a day, or give himself a sound whipping; this has a direct reference, in his opinion, to the service of God. No other motive could engage him to such austerities. By these distinguished marks of devotion, he has now acquired the divine favour; and may expect, in recompence, protection and safety in this world, and eternal happiness in the next.

And while the body is confined to one planet, along which it creeps with pain and difficulty; the thought can in an instant transport us into the most distant regions of the universe; or even beyond the universe, into the unbounded chaos, where nature is supposed to lie in total confusion. What never was seen, or heard or, may yet be conceived; not is any thing beyond the power of thought, except what implies as absolute contradiction.

Nature may certainly produce whatever can arise from habit: Nay, habit is nothing but one of the principles of nature, and derives all its force from that origin.