Changes

This is taking too much time, so just a few remarks. (1) No one is asking that sex between a couple is unrelated to procreation, all things being equal. The quote from St Maximus the Confessor doesn't really say what you seem to want it to say. He criticizes the man "who seeks in it ONLY sensual pleasure...." Moreover, I would not categorize the unitive aspect of lovemaking ever as "ONLY sensual pleasure." This is perhaps why, e.g., the Roman Catholic Church does not classify NFP as contraception. As for St Nikodemos, his theology ways in many ways quite Catholic - I shouldn't be surprised that he took a Roman view of Onan. Verse 18 of the Leviticus passage deals with emissions stemming from intercourse; vv 16-17 health dealt with nocturnal emissions. The Eastern Fathers (with the exception of Epiphanios) did not see Onan's sin as one of contraception. It was his disobedience of God and the law on Levirate marriage. There was no law about coitus interrupts.