In the case of a married couple, one may be spiritual and the other natural; we mean by spiritual one who loves spiritual things and thus has wisdom from the Lord, by natural one who loves only natural things and thus has wisdom from himself. When two such people are joined in marriage, the spiritual one feels conjugial love as heat, the natural one as coldness. Obviously heat and coldness cannot exist together, and heat cannot fire a person in a state of coldness, unless this is first dispelled; nor can coldness invade one in a state of heat, unless this is first removed. So it is that intimate love is impossible between partners, one of whom is spiritual, the other not. But there can exist a love rivalling intimate love on the part of the spiritual one, as was said in the previous section.

[2] However, intimate love cannot exist between a couple both of whom are natural, since they are both cold. Any heat they have comes from unchastity. Yet these can still live together in one household, while keeping their minds apart; they can also keep up an appearance of love and mutual friendship on their faces, however much their minds disagree. In these cases outward affections, for the most part for wealth and possessions, or for honours and high rank, can become as it were ardent. Since this ardour produces the fear of their loss, pretence between couples becomes essential for them; the main ones are those listed in sections xv-xvii below. The remaining reasons listed with them may have something in common with the reasons affecting a spiritual person mentioned above (280), but only if the natural person's prudence has a touch of intelligence.