382. (iv) The understanding corresponds to the lungs. This follows from what has been said concerning the correspondence of the will with the heart; for will and understanding are the two things which reign in the spiritual man or in the mind; and the heart and lungs are the two things which reign in the natural man or in the body; and the correspondence is between all the things of the mind and all the things of the body, as was said above; from which it follows that the will corresponds to the heart, and the understanding to the lungs. Moreover, everyone may observe in himself, both from his thought and from his speech, that the understanding corresponds to the lungs. From thought: No one can think unless the respiration agrees and harmonizes; consequently, when one is thinking quietly the breathing is quiet, if one thinks deeply the breathing is deep; the breath is drawn in and let out, the lungs contract and expand according to the thought, thus according to the influx from love, slowly, quickly, eagerly, gently, intently; indeed, if the breath be held completely, it is impossible to think except in one's spirit by its own respiration, and that is not manifestly perceptible. From speech: For not the slightest sound escapes from the mouth without the assistance of the lungs; for the sound, which is articulated into words, all comes forth by means of the trachea and epiglottis; wherefore, according to the inflation of those bellows and the opening of the passage, the voice is raised even to a shout, and according to the contraction is lowered; and, if the passage is closed, speech together with thought, ceases.