By _the probable_, we mean that which has not attained to certainty, but which nevertheless has grounds on which it claims to be believed. We call it _probable_ or _proveable_, because it both has proof and is still under conditions of proof, that is, admits of still farther proof. That which is certain, has all the proof of which the case admits. A mathematical proposition is certain on the ground of necessity, and admits of no higher proof than that which really demonstrates its truth. The divine volitions are certain on the ground of the divine perfections, and admit of no higher proof than what is found in the divine perfections. The volitions of a good created being are certain on the ground of the purity of such a being, and admit of no higher proof than what is found in this purity. But when we come to a mixed being, that is, a being of reason, and of a sensitivity corrupted totally or in different degrees, then we have place not for certainty, but for probability. As our knowledge of the future volitions of such a being can only be gathered from something now existent, this knowledge will depend upon our knowledge of the present relative state of his reason and sensitivity; but a perfect knowledge of this is in no case supposable,--so that, although our actual knowledge of this being may be such as to afford us proof of what his volitions may be, yet, inasmuch as our knowledge of him may be increased indefinitely by close observation and study, so likewise will the proof be increased. According to the definition of probability above given, therefore, our knowledge of the future volitions of an imperfect being can only amount to probable knowledge. The direction of the probabilities will be determined by the preponderance of the good or the bad in the mixed being supposed. If the sensitivity be totally corrupted, the probabilities will generally go in the direction of the corrupted sensitivity, because it is one observed general fact in relation to a state of corruption, that the enjoyments of passion are preferred to the duties enjoined by the conscience. But the state of the reason itself must be considered. If the reason be in a highly developed state, and the convictions of the right consequently clear and strong, there may be probabilities of volitions in opposition to passion which cannot exist where the reason is undeveloped and subject to the errors and prejudices of custom and superstition. The difference is that which is commonly known under the terms "enlightened and unenlightened conscience." Where the sensitivity is not totally corrupted, the direction of the probabilities must depend upon the degree of corruption and the degree to which the reason is developed or undeveloped.