Now, all these illustrations are brought to show that the mind may be caused to act;--that it may be passive in relation to the cause of its volition, and active in relation to the effect of its volition. A more striking instance could not be adduced to prove the correctness of the assertion already made, that the necessitarian confounds the motion of body with the action of mind. "A thing may be caused to act," says President Day. But how does he show this? By showing that a thing may be caused to move! "Is no _activity_ given to the ball? Is not the whirlwind _active_, when it tears up the forest?" And so he goes on, leaving the light of reason and of consciousness; now rushing into the darkness of the whirlwind; now riding "on the mountain wave;" and now plunging into the depths of "volcanic lava;"--all the time in quest of light respecting the phenomena of mind! We could have wished him to stop awhile, in the impetuous current of rhetoric, and inform us, whether he really considers, "the motion of a ball" as the same thing with the volition of the mind. If he does, then he may suppose that his illustrations are to the purpose, how great soever may be his mistake; but if he supposes there is a real difference between them, how can he ever pretend to show that mind may be caused to act, by showing that body may be caused to move? I freely admit, that body may be caused to move. Body is perfectly passive in motion; and hence, its motion may be caused. But the mind is not passive in volition; and hence the difference in the two cases. It is an error, as I have already said, pervading the views of the necessitarian, that he confounds the action of mind with the motion of body. Even Mr. Locke, who, in some places, has recognized the essential difference between them, has frequently confounded them in his reasonings and illustrations. Hence, it becomes necessary to bear this distinction always in mind, in the examination of their writings. It should be rendered perfectly clear to our minds by meditation; and never permitted to grow dim through forgetfulness. This is indispensably necessary to shut out the illusions of the senses, in order that we may have a clear and unclouded view of the phenomena of nature. Is the motion of body, then, one and the same thing with the action of mind? They are frequently called by the same name. The motion of mind, and the action of body, are very common modes of expression. Body is said to act, when it only moves; and mind is said to move, when it really acts. These metaphors and supposed analogies are intimately and inseparably interwoven into the very frame-work of our language; and hence the necessity of guarding against them in our conceptions. They are almost as subtle as the great adversary of truth; and therefore we should be constantly on the watch, lest we should be deceived or misled by them.