11. Voluntary opposed to involuntary, not to necessary.
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.
