I don;t see why it is off topic to discuss birth control. The topic as I understand it to be is Birth control and non-Catholics. What I am getting at is that NFP, when used to avoid conception, is just another method available to prevent children. Those who back the use of NFP to prevent children often say that NFP is open to life as distinct from the use of condoms which are not open to life. However, according to the statistics given out by the Couple to couple league, condoms fail 7% of the time, whereas NFP, when used correctly, fails only 1% of the time. Would not these statistics on failure of use imply that condoms are seven times more open to life than NFP?
And we have the word of the Pope concerning the secondary and primary ends of marriage:
Pope Pius XI, Casti Connubii , Dec. 31, 1930: “For in matrimony as well as in the use of the matrimonial right there are also secondary ends, such as mutual aid, the cultivating of mutual love, and the quieting of concupiscence which husband and wife are not forbidden to consider SO LONG AS THEY ARE SUBORDINATED TO THE PRIMARY END and so long as the intrinsic nature of the act is preserved.”