Yet such responses to stimuli are not necessarily unconscious and cut off from voluntary control. He who winks involuntarily when a hand is passed before his eyes may become conscious that he has done so, and may, if he chooses, even acquire some facility in controlling the reflex. One may resist the tendency to swallow when the throat is dry, may hold back a sneeze, or may keep rigid the hand that is pricked by a pin. That is to say, actions in their origin mechanical and independent of choice may be raised out of their low estate, made the objects of attention, and brought within the domain of deliberate choice. Furthermore, many actions which, at the outset, claimed conscious attention and were deliberately willed may become so habitual that the doer lapses into unconsciousness or semi-unconsciousness of his deed. They take on the nature of acquired reflexes. The habit of acting appears to have been acquired by the mind and then turned over to the body, that the mind may be free to occupy itself with other activities. The man has become less the doer than the spectator of his acts; perhaps he is even less than that, he is the stage upon which the action makes its appearance, while the spectator is his neighbor. The complicated bodily movements called into play when one bites one's nails had to be learned. It requires no little ingenuity to accomplish the act when the nails are short. Yet one may come to the stage of perfection at which one bites one's nails when one is absorbed in thought about other things. And one may learn to slander one's neighbor almost as mechanically and unthinkingly as one swallows when the throat is dry. When we speak of man's impulses, we are using a vague word. There are impulses which will never be anything more. There are impulses which may become something more. There are impulses which are no longer anything more. Impulses have their psychic aspect. At its lower limit, impulse may appear very mechanical; at its upper, one may hesitate to say that desire and will are wholly absent. It is not wise to regard impulse as lying wholly beyond the sphere of will.