《道德原则研究·第一章·道德的一般原则》第3节
The end of all moral speculations is to teach us our duty; and, by proper representations of the deformity of vice and beauty of virtue, beget correspondent habits, and engage us to avoid the one, and embrace the other. But is this ever to be expected from inferences and conclusions of the understanding, which of themselves have no hold of the affections or set in motion the active powers of men? They discover truths: but where the truths which they discover are indifferent, and beget no desire or aversion, they can have no influence on conduct and behaviour. What is honourable, what is fair, what is becoming, what is noble, what is generous, takes possession of the heart, and animates us to embrace and maintain it. What is intelligible, what is evident, what is probable, what is true, procures only the cool assent of the understanding; and gratifying a speculative curiosity, puts an end to our researches. Extinguish all the warm feelings and prepossessions in favour of virtue, and all disgust or aversion to vice: render men totally indifferent towards these distinctions; and morality is no longer a practical study, nor has any tendency to regulate our lives and actions. These arguments on each side (and many more might be produced) are so plausible, that I am apt to suspect, they may, the one as well as the other, be solid and satisfactory, and that reason and sentiment concur in almost all moral determinations and conclusions. The final sentence, it is probable, which pronounces characters and actions amiable or odious, praise-worthy or blameable; that which stamps on them the mark of honour or infamy, approbation or censure; that which renders morality an active principle and constitutes virtue our happiness, and vice our misery; it is probable, I say, that this final sentence depends on some internal sense or feeling, which nature has made universal in the whole species. For what else can have an influence of this nature? But in order to pave the way for such a sentiment, and give a proper discernment of its object, it is often necessary, we find, that much reasoning should precede, that nice distinctions be made, just conclusions drawn, distant comparisons formed, complicated relations examined, and general facts fixed and ascertained. Some species of beauty, especially the natural kinds, on their first appearance, command our affection and approbation; and where they fail of this effect, it is impossible for any reasoning to redress their influence, or adapt them better to our taste and sentiment. But in many orders of beauty, particularly those of the finer arts, it is requisite to employ much reasoning, in order to feel the proper sentiment; and a false relish may frequently be corrected by argument and reflection. There are just grounds to conclude, that moral beauty partakes much of this latter species, and demands the assistance of our intellectual faculties, in order to give it a suitable influence on the human mind.
注释摘要
这一段，休谟干了两件事：他先把道德推到了「理解」够不着的地方，然后又小心地把理解拉了回来，给了它一个辅助的位置。 他出发的前提是一个大家都比较容易承认的事实：一切道德思考，说到底，是要教人晓得自己的本分，是要通过把恶描绘得丑陋、把德性描绘得美好，来养成习惯，让人避开前者、拥抱后者。问题在于，单凭理解推出来的结论，自己就能做到这一点吗？休谟的回答很干脆：不能…