ing as the mind shall choose or direct. Our idea of liberty reaches as far as that power, and no farther. For wherever restraint comes to check that power, or compulsion takes away that indifferency of ability on either side to act, or to forbear acting, there liberty, and our notion of it, presently ceases.
Voluntary opposed to involuntary, not to necessary.§ 11. We have instances enough, and often more than enough, in our own bodies. A man's heart beats, and the blood circulates, which it is not in his power by any thought or volition to stop; and therefore in respect of these motions, where rest depends not on his choice, nor would follow the determination of his mind, if it should prefer it, he is not a free agent. Convulsive motions agitate his legs, so that, though he wills it ever so much, he cannot by any power of his mind stop their motion (as in that odd disease called chorea sancti viti), but he is perpetually dancing: he is not at liberty in this action, but under as much necessity of moving as a stone that falls, or a tennis-ball struck with a racket. On the other side, a palsy or the stocks hinder his legs from obeying the determination of his mind, if it would thereby transfer his body to another place. In all these there is want of freedom; though the sitting still even of a paralytic, whilst he prefers it to a removal, is truly voluntary. Voluntary then is not opposed to necessary, but to involuntary. For a man may prefer what he can do to what he cannot do; the state he is in to its absence or change, though necessity has made it in itself unalterable.
Liberty, what.§ 12. As it is in the motions of the body, so it is in the thoughts of our minds: where any one is such that we have power to take it up, or lay it by, according to the preference of the mind, there we are at liberty. A waking man being under the necessity of having some ideas constantly in his mind, is not at liberty to think or not to think, no more than he is at liberty, whether his body shall
