The theory that the will is in action during sleep is, therefore, to my mind untenable. It has probably had its origin in the idea that confounds it with desire, from which it differs so markedly that it seems strange the distinction should ever fail of being made. Locke[62] points out very clearly the differences between the two faculties. In fact they may be exerted in directly opposite ways. Desire often precedes volition; but we all, at times, will acts which are contrary to our desire, and desire to perform others which we are unable to will. Reid[63] writes with great perspicuity on this distinction between desire and will. He says: “Desire and will agree in this, that both must have an object of which we must have some conception; and, therefore, both must be accompanied with some degree of understanding. But they differ in several things. “The object of desire may be anything which appetite, passion, or affection leads us to pursue; it may be any event which we think good for us, or for those to whom we are well affected. I may desire meat or drink, or ease from pain. But to say that I will meat, or will drink, or will ease from pain, is not English. There is, therefore, a distinction in common language between desire and will. And the distinction is, that what we will must be an action and our own action; what we desire may not be our own action, it may be no action at all. “A man desires that his children may be happy, and that they may behave well. Their being happy is no action at all; their behaving well is not his action but theirs. “With regard to our own actions, we may desire what we do not will, and will what we do not desire; nay, what we have a great aversion to. “A man athirst has a strong desire to drink; but for some particular reason he determines not to gratify his desire. A judge from a regard to justice and to the duty of his office dooms a criminal to die; while, from humanity or particular affection, he desires that he should live. A man for health may take a nauseous draught, for which he has no desire, but a great aversion. Desire, therefore, even when its object is some action of our own, is only an incitement to will; but it is not volition. The determination of the mind may be not to do what we desire to do. But as desire is often accompanied by will, we are apt to overlook the distinction between them.”