407. That this is so can be proved to the life by the conjunction of the heart with the lungs, because the correspondence between the will and the heart, and between the understanding and the lungs, is such that just as the love acts with the understanding spiritually, so does the heart act with the lungs naturally: from this, what has been said above can be seen as in an image presented to the eye. That man has neither any sensitive life nor any active life, so long as the heart and the lungs do not act together, is evident from the state of the fetus or the infant in the womb, and from its state after birth. So long as man is a fetus, that is, in the womb, the lungs are closed, wherefore he has no feeling nor any action; the organs of sense are closed up, the hands are bound, likewise the feet; but after birth the lungs are opened, and as they are opened man feels and acts; the lungs are opened by means of the blood sent into them from the heart. That man has neither sensitive life nor active life without the co-operation of the heart and the lungs, is evident also in swoons, when the heart alone acts, and not the lungs, for respiration then ceases; in this case there is no sensation and no action, as is well known. It is the same with persons suffocated, either by water or by anything obstructing the larynx and closing the respiratory passage; it is well-known that the man then appears to be dead, he feels nothing and does nothing; and yet he is alive in the heart; for he returns to both his sensitive and his active life as soon as the obstructions to the lungs are removed. The blood, it is true, circulates in the meantime through the lungs, but through the pulmonary arteries and veins, not through the bronchial arteries and veins, and these last are what give man the power of breathing. It is the same with the influx of love into the understanding.