_What Evidence of Correctness._--How are we to know, then, whether conscience judges right? What voucher have we for its correctness? How far is it to be trusted in its perceptions and decisions? Perhaps we are so constituted, it may be said, as invariably to judge that to be right which is wrong, and the reverse, and so to approve where we should condemn. True, we reply, this may be so. It may be that I am so constituted, that two and two shall _seem_ to be four, when in reality they are five; and that the three angles of a triangle shall _seem_ to be equal to two right angles, when in reality they are equal to three. This may be so. Still it is a presumption in favor of the correctness of all our natural perceptions, that they are the operation of original principles of our constitution. It is not probable, to say the least, that we are so constituted by the great Author of our being, as to be habitually deceived. It may be that the organs of vision and hearing are absolutely false; that the things which we see, and hear, and feel, through the medium of the senses, have no correspondence to our supposed perceptions. But this is not a probable supposition. He who denies the validity of the natural faculties, has the burden of proof; and proof is of course impossible; for the simple reason, that, in order to prove them false, you must make use of these very faculties; and if their testimony is not reliable in the one case, certainly it is not in the other. We must then take their veracity for granted; and we have the right to do so. And so of our moral nature. It comes from the Author of our being, and if it is uniformly and originally wrong, then he is wrong. It is an error, which, in the nature of the case, can never be detected or corrected. We cannot get beyond our constitution, back of our natural endowments, to judge, _à priori_, and from an external position, whether they are correct or not. Right and wrong are not, indeed, the creations of the divine will; but the faculties by which we perceive and approve the right, and condemn the wrong, are from him; and we must presume upon their general correctness. _Not infallible._--It does not follow from this, however, nor do we affirm, that conscience is infallible, that she never errs. It does not follow that our moral perceptions and judgments are invariably correct, because they spring from our native constitution. This is not so. There is not one of the faculties of the human mind that is not liable to err. Not one of its activities is infallible. The reasoning power sometimes errs; the judgment errs; the memory errs. The moral faculty is on the same footing, in this respect, with any and all other faculties.