372. (i) All things of the mind have relation to the will and understanding, and all things of the body to the heart and lungs. By the mind nothing else is understood than the will and understanding, which in their entirety are all the things that affect a man and all he thinks of, thus all things of man's affection and thought. Those things by which man is affected belong to his will, and those of which he thinks belong to his understanding. It is known that all the things of man's thought belong to his understanding, since he thinks from the understanding. But it is not so well known that all the things of man's affection belong to his will, because when he thinks, he pays no heed to the affection, but only to what he is thinking; just as when he hears somebody speaking, he pays attention not to the sound, but to the words themselves; when yet affection stands in the same relation to thought as sound does to the spoken word. Consequently one knows from the sound of a speaker's voice what his affection is, and from the words what his thought is. Affection belongs to the will because every affection belongs to love, and the receptacle of love is the will, as was shown above. He who does not know that affection belongs to the will confuses affection with the understanding, for he declares it to be one with thought; yet they are not one although they act as one. That they are confused is clear from the common expression "I think I shall do this," meaning, "I will do it." But that they are two things is also clear from a common expression, "I wish to think over this matter", and when he thinks it over, the affection of the will is present in the thought of the understanding, just as sound is present in the spoken word, as was said before. That all things of the body have relation to the heart and lungs is well known, but that there is a correspondence of the heart and lungs with the will and the understanding is not known. This subject will therefore be discussed in what follows.