449. Anyone can see by his general powers of perception that the lust for fornicating is not a lust for adultery. Would any law or any judge bring the same charge against a fornicator as against an adulterer? The reason why this is generally seen is that fornication is not opposed to conjugial love, as adultery is. Conjugial love can be hidden within fornication, just as the spiritual can be hidden within the natural. In fact, the spiritual actually develops from the natural; and once it has developed, then the natural surrounds it, like bark around a piece of wood or a sheath around a sword, and it serves to protect the spiritual from violence. From this it is obvious that natural love for the other sex as a whole precedes spiritual love, which is for one of the other sex. However, if fornication is the result of natural sexual love, it can be wiped out, so long as conjugial love is regarded as the chief good, and this is preferred and sought.
[2] It is quite different with the lustful and obscene love of adultery, which was shown in the last chapter on the opposition of scortatory and conjugial love to be opposed to conjugial love and to destroy it. If therefore a deliberate and confirmed adulterer for various reasons enters a marriage bed, the reverse happens; the natural with its wantonness and obscenity lies hidden within, and an appearance of spirituality covers it up outwardly. These considerations will enable the reason to see that the lust for restricted fornication is, as compared with the lust for adultery, like the first warmth as compared with midwinter cold in arctic regions.