/summa/XP/XPII/XP_Q39:
We must next consider the impediments to this sacrament. Under this head there are six points of inquiry:
(1) Whether the female sex is an impediment to receiving this sacrament?
(2) Whether lack of the use of reason is?
(3) Whether the state of slavery is?
(4) Whether homicide is?
(5) Whether illegitimate birth is?
(6) Whether lack of members is?