5017. And it came to pass when he heard. That this signifies when it was perceived, is evident from the signification of "hearing," as being to obey, and also as being to perceive. That it means to obey may be seen above (n. 2542, 3869); that it means also to perceive is plain from the very function of the ear, and hence from the nature of the hearing. The function of the ear is to receive another's speech and convey it to the common sensory, in order that the sensory may perceive what the other person is thinking, so that "to hear" is to perceive. Thus it is the nature of the hearing to transfer what anyone is speaking from his own thought into the thought of another, and from the thought into his will, and from the will into act; hence "to hear" is to obey. These two offices are proper to the hearing. In the languages these are distinguished by "hearing" anyone, which is to perceive, and by "listening," or "hearkening" to anyone, which is to obey. That these two offices belong to hearing is because man cannot communicate the things of his thought, and also the things of his will, by any other way; nor can he otherwise persuade and by reasons induce others to do and to obey what he wills. From all this it is evident by what a circle communications are effected-from will into thought, and so into speech; and from speech through the ear into another's thought and will. Hence also it is that the spirits and angels who correspond to the ear or to the sense of hearing in the Grand Man, are not only perceptions, but also obediences. That they are obediences, may be seen above (n. 4652-4660); and because they are obediences, they are also perceptions, for the one involves the other.