I was just looking through the paper for some inspiration for my daily blog post, and discovered the Pope has just approved the use of condoms to prevent the spread of infections.
It always seemed like such an obvious moral argument to me.
A person not using a condom would commit the moral sin of adultery - causing emotional hurt and moral corruption - and add to it the more physical sin of exposing their partner(s) to potentially lethal infections. Clearly, it is arithmetically better to commit just the one sin and mitigate it by doing it responsibly?
And there is a difference between the two sins as well. I would say that the emotional harm and moral corruption are limited in scope and reversible. That sin can be corrected. However, the physical infection is at present medically incurable and thereby not reversible by any measure of repentance or conversion (unless you count on miracles - but even if you believe in those, they will never cure millions but only individuals). Also, the physical infection may be passed on to innocents like babies or the unwitting spouse of an infected cheater. Doctrine states that God has given you a body and the duty to look after it, and using a condom when 'the spirit is weak' at least leaves 'the flesh' intact so the person can live on and perhaps even strengthen their spirit.
Although I am quite romantically partial to the idea of marriage and faithfulness, I'm not saying I agree with the Church on their definitions of sins and morals. I just find it so simple to defend the use of condoms entirely in accordance with their own doctrines and beliefs, that I've always been surprised with their view on safe sex.
Perhaps there's hope yet.