3635. There are in the human body two things which are the fountains of all its motion, and also of all external or mere bodily action and sensation, namely, the heart and the lungs. These two correspond in such a manner to the Grand Man or heaven of the Lord that the celestial angels therein constitute one kingdom, and the spiritual another kingdom, for the kingdom of the Lord is celestial and spiritual. The celestial kingdom consists of those who are in love to the Lord; the spiritual kingdom of those who are in charity toward the neighbor (n. 2088, 2669, 2715, 2718, 3235, 3246). The heart and its kingdom in man correspond to the celestial angels; the lungs and their kingdom correspond to the spiritual. The angels also flow into the things which are of the heart and lungs, so that these things exist and subsist by influx from them. But the correspondence of the heart and lungs with the Grand Man will of the Lord's Divine mercy be treated of specifically.