401. (3) Love or the will is unable to effect anything by its human form without a marriage with wisdom or the understanding.  This also is evident from the correspondence of the heart with the will.  The embryo man lives by the heart, not by the lungs.  For in the fetus the blood does not flow from the heart into the lungs, giving it the ability to respire; but it flows through the foramen ovale into the left ventricle of the heart; consequently the fetus is unable to move any part of its body, but lies enswathed, neither has it sensation, for its organs of sense are closed.  So is it with love or the will, from which the fetus lives indeed, though obscurely, that is, without sensation or action.  But as soon as the lungs are opened, which is the case after birth, he begins to feel and act, and likewise to will and think.  From all this it can be seen, that love or the will is unable to effect anything by means of its human form without a marriage with wisdom or the understanding.

402. (4) Love or the will prepares a house or bridal chamber for its future wife, which is wisdom or the understanding.  In the created universe and in each of its particulars there is a marriage of good and truth; and this is so because good is of love and truth is of wisdom, and these two are in the Lord, and out of Him all things are created.  How this marriage has existence in man can be seen mirrored in the conjunction of the heart with the lungs; since the heart corresponds to love or good, and the lungs to wisdom or truth (see above, n. 378-381, 382-385).  From that conjunction it can be seen how love or the will betroths to itself wisdom or the understanding, and afterwards weds it, that is, enters into a kind of marriage with it.  Love betroths to itself wisdom by preparing for it a house or bridal chamber, and marries it by conjoining it to itself by affections, and afterwards lives wisely with it in that house.  How this is cannot be fully described except in spiritual language, because love and wisdom, consequently will and understanding, are spiritual; and spiritual things can, indeed, be expressed in natural language, but can be perceived only obscurely, from a lack of knowledge of what love is, what wisdom is, what affections for good are, and what affections for wisdom, that is, affections for truth, are.  Yet the nature of the betrothal and of the marriage of love with wisdom, or of will with understanding, can be seen by the parallel that is furnished by their correspondence with the heart and lungs.  What is true of these is true of love and wisdom, so entirely that there is no difference whatever except that one is natural and the other spiritual.  Thus it is evident from the heart and lungs, that the heart first forms the lungs, and afterwards joins itself to them; it forms the lungs in the fetus, and joins itself to them after birth.  This the heart does in its abode which is called the breast, where the two are encamped together, separated from the other parts of the body by a partition called the diaphragm and by a covering called the pleura.  So it is with love and wisdom or with will and understanding.