It has been said that marriage love, which is natural, descends from the love of good and truth, which is spiritual; this spiritual therefore is in the natural love of marriage as a cause is in its effect.  So from the marriage of good and truth there comes forth a love of bearing fruit, that is, good through truth and truth from the good; and from that love a love of producing offspring descends, and in that love there is every delight and pleasure.

On the contrary, love of adultery, which is natural, springs from a love of evil and falsity, which is spiritual; consequently this spiritual is in the natural love of adultery as a cause is in its effect.  So from the marriage of evil and falsity by love there comes forth a love of bearing fruit, namely, evil through falsity and falsity from evil; and from that love a love of producing offspring in adulteries descends, and in that love there is every delight and pleasure.

There is every delight and pleasure in the love of producing offspring, because all that is delightful, pleasurable, blessed, and happy, in the whole heaven and in the whole world, has been from creation brought together into the effort and thus into the act of bringing forth uses; and these joys increase in an ascending degree to eternity, according to the goodness and excellence of the uses.  This make evident why the pleasure of producing offspring, which surpasses every other pleasure, is so great.  It surpasses every other because its use, which is the procreation of the human race, and thus of heaven, surpasses all other uses.

From this, too, comes the pleasure and delight of adultery; but as prolification by adulteries corresponds to the bringing forth of evil through falsity and of falsity from evil, that pleasure or delight decreases and becomes vile by degrees until it is changed at last into aversion and disgust.  Because, as has been said above, the delight of the love of marriage is a heavenly delight, so the delight of adultery is an infernal delight, so the delight of adultery is from a certain impure fire, which as long as it lasts, counterfeits the delight of the love of good, but in itself it is the delight of the love of evil, which is in its essence the delight of hatred against good and truth.  And because this is its origin there is not love between an adulterer and an adulteress except such as the love of hatred is, which is such that they can be in conjunction in externals but not in internals.  For in the externals there is something fiery, but in the internals there is coldness; therefore after a short time the fire is extinguished and coldness succeeds, either with impotence or a turning away as from something filthy.

It has been granted me to see that love in its essence, and it was such that within it was deadly hatred, while without it appeared like a fire from burning dung and putrid and stinking matters.  And as that fire with its delight burnt out, so by degrees the life of mutual discourse and intercourse expired, and hatred came forth, manifested first as contempt, afterward as aversion, then as rejection, and finally as abuse and contention.  And what was wonderful, although they hated each other they could from time to time come together and for the time feel the delight of hatred as the delight of love; but this came from a hankering of the flesh.