in the odors that correspond to a love opposed to wisdom; these are foul odors, but the former are fragrant.  It follows that men in the world impregnate their blood with similar things according to correspondence with the affections of their love; for what the spirit of a man loves, his blood according to correspondence craves and by respiration attracts.  From this correspondence it results that man as regards his love is purified if he loves wisdom, and is defiled if he does not love it.  Moreover, all purification of man is effected by means of the truths of wisdom, and all pollution of man is effected by means of falsities that are opposite to the truths of wisdom.

421. (17) Love or the will is defiled in the understanding and by it, if they are not elevated together.  This is because love, if not elevated, remains impure (as stated above, n. 419, 420); and while it remains impure it loves what is impure, such as revenges, hatreds, deceits, blasphemes, adulteries, for these are then its affections that are called lusts, and it rejects what belongs to charity, justice, sincerity, truth, and chastity.  Love is said to be defiled in the understanding, and by it; in the understanding, when love is affected by these impure things; by the understanding, when love makes the things of wisdom to become its servants, and still more when it perverts, falsifies, and adulterates them.  Of the corresponding state of the heart, or of its blood in the lungs, there is no need to say more than has been said above (n. 420), except that instead of the purification of the blood its defilement takes place; and instead of the nutrition of the blood by fragrant odors its nutrition is effected by stenches, precisely as it is respectively in heaven and in hell.

422. (18) Love, when purified by wisdom in the understanding, becomes spiritual and celestial.  Man is born natural, but in the measure in which his understanding is raised into the light of heaven, and his love conjointly is raised into the heat of heaven, he becomes spiritual and celestial; he then becomes like a garden of Eden, which is at once in vernal light and vernal heat.  It is not the understanding that becomes spiritual and celestial, but the love; and when the love has so become, it makes its consort, the understanding, spiritual and celestial.  Love becomes spiritual and celestial by a life according to the truths of wisdom which the understanding teaches and requires.  Love imbibes these truths by means of its understanding, and not from itself; for love cannot elevate itself unless it knows truths, and these it can learn only by means of an elevated and enlightened understanding; and then so far as it loves truths in the practice of them so far it is elevated; for to understand is one thing and to will is another; or to say is one thing and to do is another.  There are those who understand and talk about the truths of wisdom, yet neither will nor practise them.  When, therefore,