We may appeal, in the first place, to the truth implied in the very expression the _Moral Law_. But it must be explained that by the term moral law we do not mean a code of five, ten, or fifty commandments, but simply the expression of the ethical "ought," the announcement of the supreme fact of moral obligation in general, that is, the duty of unconditionally obeying the right when the right is known to us. It is no more the duty of the moral law to set about codifying laws than it is of the conscience to practise casuistry. Conscience is not a theoretical instructor, but a practical commander. The intelligence, the reason in man it is to which is allotted the function of formulating laws and of deciding what is and what is not in conformity with right. Once that is decided, according to its light, by the reason, then conscience steps in and authoritatively commands that the right is to be unconditionally obeyed. And this, of course, solves that venerable objection that conscience can be no guide because moral codes have changed and are changing, and are not alike in various ages and countries. Conscience has nothing to do with the excesses of Torquemada, or libidinous rites of Astarte. Reason was at fault, not conscience, and that supreme judge, misguided by the reason, appeared to give a false judgment, whereas, true to itself for ever, it simply pronounced in each and every instance, that the right must be obeyed. Like the needle in the compass, it undeviatingly points to the polar star of duty. Let us proceed with our analysis of the conception of the moral law. There are various schools of ethics, but they are all united in maintaining _some_ obligatory force in morality, that whatever may be the precise meaning of the solemn word right, the right is binding on the allegiance of our will. Hence Emerson, of the rational school, is philosophically accurate when he deduces purity of heart, or uprightness of intention, and the law of gravitation from the same source. They are both laws, one valid in the spheres, the other valid among men, the one only difference being that whereas the spheres compulsorily obey the law of their existence, man by the noble obeisance of his will--an obeisance which, as Kant points out, raises him to an immeasurable dignity--voluntarily submits himself to his law, and thereby fulfils the purpose of his life.