The doctrine of liberty is as inevitably connected with the _observed_ nature of a volition, as that of necessity is connected with its assumed nature. I would not say that we are conscious of liberty; for that would not be correct; but I will say, that we are conscious of that which necessarily leads to the conviction that we are free, that we have a power of contrary choice. I would not say with Dr. Clarke, that liberty consists in a power to act; but I will say, that it necessarily results from it. I would not say, that we are conscious of the existence of no producing cause of our volitions; for we cannot be conscious of that which does not exist. But I will say, that as we are conscious of the existence of an act, so we see and do know that this is not a passive impression, or a produced effect. And as we are not compelled to act, so we know that we may act or may not act, so we know that our actions are not necessitated, but may be put forth or withheld. This is liberty, this is "a power of contrary choice." This idea of liberty, I say, follows from the fact of consciousness that we do act, by an inference as clear as noonday; by an inference so natural, so direct, and so inconceivably rapid, that it has often been supposed to be included in the testimony of consciousness itself. No man could help the conclusion, if he would only allow his reason to speak for itself. Is this doctrine any the less certain, because it is a matter of inference? It will be conceded that it is not. The most unquestionable facts in the universe are made known by the same kind of evidence. It is sometimes said, that we are conscious of our own existence; but this is not to use language with philosophical precision. We are merely conscious of the existence of thought, of feeling, of volition; and we are so made, that we are compelled to believe that there is something which thinks, and feels, and wills. It is thus, by what has been called a fundamental law of belief, that we arrive at the knowledge of the existence of our minds. In like manner, from the fact of consciousness that we do act, or put forth volitions, we are forced, by a fundamental law of belief, to yield to the conviction that we are free. This inference as necessarily results from the observed phenomena of the mind, as the existence of the mind itself results from the same phenomena. And if the doctrine of the necessitarian were true, that volition is a produced effect, we should never infer from it that we have _a power of acting_ at all; we should simply infer that we are _susceptible of passive impressions_.