As I understand the traditional hard-line Catholic position, it boils down to not having sex if you don't want children. (Rhythmn method excepted). On the other hand, I know of fundamentalist protestants who would not even practice the rhythmn method, because that would be disobeying the Genesis command to go forth and multiply; that includes a preacher who decided that he had sinned in getting a vasectomy, and had the procedure successfully reversed.
Guest from Sanity, do you lean to either of these positions, or do you find them as untenable as I do?