We now enter a sphere of which no understanding could by any possibility ever guess, much less investigate. Here no sense could ever penetrate; there is no object for it to perceive. Here all judgments are impertinent; for in this sphere are only laws, and duties, and obligations. An understanding cannot "conceive" of a moral law, because such a law is inconceivable; and it cannot perceive one, because it has no eye. If it were competent to explain every phenomenon in the other classes, it would be utterly impotent to explain a single phenomenon in this. What is moral obligation? Whence does it arise, or how is it imposed? and who will enforce it, and how will it be enforced? All these, and numerous such other questions, cannot be raised even by the Understanding, much less answered by it. The moral law of the Universe is one which can be learned from no judgment, or combination of judgments. It can be learned only by being _seen_. The moral law is no conclusion, which may be modified by a subsequent experience. It is an affirmation which is _imperative_. To illustrate. It is an axiom, that the fact of free moral agency involves the fact of obligation. Man is a free moral agent; and so, under the obligation imposed. At the first, it was optional with the Deity whether he would create man or not. But will any one assert that, having determined to create man such as he is, it was optional with him, whether man should be under the obligation, or not? Can man be a free moral agent, and be free from the duties inherent therein? Does not the mind instinctively and necessarily affirm, that the fact of free moral agency assures the fact of such a relation to God's moral government, that obligation _must_ follow? One cannot hesitate to say, that the formula, A free agent may be released from his obligation to moral law, is absolutely unthinkable.