William of Pagula was a bit more lenient in his view that it was not sinful to marry for sexual attraction, so long as this was not the primary reason (Brundage, 430).
Consistently, procreation, or "the divine plan" of continuing the race, was seen as the only acceptable end to marital relations.
In II.10 of the , Messer Ricciardo di Chinzica, who cannot keep up with his younger, lustier wife, finds a similar way to limit their sex life: For he made it clear to her that there was not a single day that was not the feast of one or more Saints, out of respect for whom... To the foregoing, he added holidays of obligation, the four Ember weeks, the eves of the Apostles and a numerous array of subsidiary Saints, Fridays and Saturdays, the Sabbath, the whole of Lent, certain phases of the moon, and various special occasions...
For a long time (much to the chagrin of his lady, whose turn came round once a month at the most) he abided by this régime...(179-80) In addition to prescribing when couples might have intercourse, the church also provided instructions for marital coitus.
Evidence for the first opinion can be found in Boccaccio's tale about Sophronia, who weds Giusippus but consummates the marriage with his friend Titus, who thus becomes her "real" husband (X.8) (Brundage, 456).
Granted, this story takes place in Greece and not in medieval Italy, but it does seem consistent with the popular view that physical consummation was what determined the validity of a marriage.
According to Hostensius, once a girl was physically ready to consummate a sexual relationship, she was ready for marriage, and the same was true for boys.
However, since puberty came earlier for females than males, they could marry at a younger age (usually, he said, girls were ready at age twelve and boys at age fourteen) (Brundage, 434).
The, a handbook for confessors published during the early thirteenth century, listed some of the times in which sexual activity between husband and wife was not permitted, which included all feast and fast days, on Sundays, and at all times when the woman was considered "unclean" (during menstruation or pregnancy, while she was breast-feeding, and for forty days after childbirth).
This meant that, on average, most married couples could legally have sex less than once a week (Richards, 28-29).