Now I cannot perceive why there is any more difficulty in annexing a meaning to the word liberty, as it relates to the faculties of the mind than as it relates to those of the body, or why a treatise of the one should be a treatise of effects without a cause any more than of the other. If the distinction between liberty and necessity is lost in this case, it is not because liberty but because necessity can have no place in the will, or because we cannot easily put a padlock on the mind. If the prisoner who has his chains struck off, walks or runs, dances or leaps, is this an instance of an effect without a cause, because it is an effect of liberty, or of what Helvetius calls the free exercise of his power? Not that he can exert this power without means or motives, that is, without ground to move on, or limbs to move with, or breath to draw, or will to impel him, but ‘with all these means and appliances to boot’ he has a power to do certain things which his chains deprived him of the liberty of doing, but which the striking them off restores to him again. Why then, if liberty does not in its common sense signify an effect without a cause, but the free exercise of a power, did it not signify the same thing or something similar as applied to the mind? Has the mind no powers, or are they necessarily impeded and hindered from operating? My notion of a free agent, I confess, is not that represented by Mr. Hobbes, namely, one that when all things necessary to produce the effect are present can nevertheless not produce it; but I believe a free agent of whatever kind, is one which where all things necessary to produce the effect are present, can produce it; its own operation not being hindered by any thing else. The body is said to be free when it has the power to obey the direction of the will: so the will may be said to be free when it has the power to obey the dictates of the understanding. The absurdity of the libertarians is in supposing that liberty of action, and liberty of will have the same identical source, viz. the will; or that as it is the will that moves the body, so it is the will that moves itself in order to be free.