It is of the utmost importance to preserve a clear distinction between the unconscious forces of matter and the intelligent ones of mind; otherwise we shall inevitably be misled by such expressions as “the forces of nature.” It is impossible to argue the question unless the distinction is admitted as a fact, whatever theory may be held about their origin. It is absurd to confound principles so distinct as heat, or gravitation, or electricity, with those which produce the most disinterested moral actions, and designate them by the common term “natural forces.” In common language we are in no danger of error when we speak of the force of conscience, or the force of a motive; but in discussions like the present, where such expressions really involve the assumption of the whole controversy, it is absurd to classify such phenomena, and the unintelligent forces of matter under a common designation, unless it can be demonstrated that they are all manifestations of the same power. We come now to the much vexed question as to the meaning to be attached to the words “miracle” and “miraculous;” and the terms closely allied to them, “supernatural” and “superhuman.” Is there any valid distinction between miracles and supernatural occurrences? Are, in fact, all miracles supernatural occurrences, and all supernatural occurrences miracles? The determination of this question is closely connected with an important point which will be considered hereafter, viz., whether a miracle could have any evidential value if it were brought about by a special adaptation of the known or unknown forces of material nature. Let it be observed that we are not discussing this question as a purely abstract one, but in reference to the truth of Christianity. What miracles may be in themselves, I shall not inquire; but in relation to the question before us, what we mean when we call an occurrence a miracle ought to be made sufficiently clear and distinct. In this controversy it would greatly tend to precision if we used the term “miracle” as distinguished from an occurrence which is supernatural or superhuman, to denote only those supernatural occurrences which have an evidential value in connection with the evidences of a divine revelation, since there may be supernatural occurrences which would not be in any proper sense evidential.