First, sexual intercourse is only licit, or permissible within the confines of a sacramental marriage.
Second, the BCP is only a medication. If a woman is prescribed the BCP for “health reasons”, that is, some medical condition that requires her to take the drug, then as a medical treatment it is permissible as far as I know.
Third, what makes sexual intercourse sinful between a man and woman, within the confines of a sacramental marriage, is dependent upon a number of factors. A normal healthy couple who uses the BCP as a contra-ceptive (against conception) device is indeed sinning, though upon whom the pain of that sin falls, and the severity of that sin (venal or mortal) is dependent upon the formation of that individual(s), and the intent or reason(s) they took up that treatment. A completely un-cathecized individual, ignorant of the consequences of their actions, cannot be held culpable of mortal sin if they use contraception. There are instances where couples are led to use contraception because someone in authority within the Church says they could - perhaps even some priests. That permission does not make it “sinless”, but does affect whether the sin can be considered “mortal”.
As another example, if a woman decides to take the BCP without the husbands consent, he cannot be forced to engage in the martial embrace. If he should decide, for the good of the marriage, that engaging in the act would be charitable and appropriate, he may do so for the sake of the marriage without incurring the pain of sin. He, of course, needs to keep in mind that if his wife is on a multi-phasic Pill, and the ovulation suppression mechanism on the BCP does not work, the other mechanisim that makes the uterus hostile to implanation may work as an abortifacient, and he may be unwittingly contributing to the death of a child. He must weigh the decision to have relations with his wife in this context.
If a man sterilizes himself with a vasectomy, then he may suffer the the pain of mortal sin(under the conditions detailed above, for instance), though his wife is less culpable to a degree. If it was a mutally agreed upon process, then a spritual director may discern that she too is under the pain of mortal sin. If the man in question examines his conscience throughly, does repent of that sin, confesses that sin to a priest under the typical parameters of the sacrament of reconciliation, he will be forgiven of that sin fully. From that point on, marital relations will not automatically incur the pain of sin on either partner. The Church does not require a man to get a reversal of a vasectomy to return to sacramental communion with our Lord.
Any other natural occurance of sterilization will not incur the pain of sin upon sexual intercourse within the confines of a sacramental marriage.
These are may poor explanations of my understanding of these issues, and I welcome correction on these views from any better skilled apologist if available, and particularly from any priests on these boards.
Pax Christi,
John
