The reason is that the male is destined by birth to become an intellect, the female to become a will which loves the male's intellect. It follows from this that in marriage a wife's will is linked with her husband's intellect, and the husband's intellect is reciprocally linked with his wife's will. Anyone can see that the linking of intellect and will is the closest, and that it is so in order that one faculty can enter into the other and be delighted as the result of and in that linking.