We must now consider the plurality of wives. Under this head there are five points of inquiry:

(1) Whether it is against the natural law to have several wives?

(2) Whether this was ever lawful?

(3) Whether it is against the natural law to have a concubine?

(4) Whether it is a mortal sin to have intercourse with a concubine?

(5) Whether it was ever lawful to have a concubine?