Firstly, consider this comment by Rev. Gifford A. Grobien over at Four and Twenty Blackbirds:
...Dr. Heidenreich is correct in his account of the history of interpretation of contraception, but Rev. Brown challenges the validity of this interpretation because he does not see the argument in Scripture. The two gentlemen thus have not merely different opinions about contraception or the interpretation of this or that passage of Scripture, but they demonstrate epistemologies at odds. The interpretation offered by Dr. Heidenreich is a classical interpretation that operates out of ontological assumptions: what a creature does is related to who or what it is, and who or what it is is not simply the observable properties and characteristics, but the purpose for which the creature exists and the relationship he is engaged in. When purpose and relationship is assumed, then attributes are less likely to be seen as independent and incidental, but integrated with each other attributes and with other creatures. In other words, for human beings, because semen is emitted through sexual excitement which deepens the emotional bonds between the male and female, sexual relations are for procreation, satisfying sexual urges, and building loving unity. They all go together, and cannot be separated in an independent way, as if each aspect was unimportant for the flourishing of the other aspects.
The interpretation offered by Rev. Brown, on the other hand, even if he does not like it, is a modernist one. Yes, the skeptical aspect is postmodern. But what is fundamental is his move away from a holistic understanding of purpose that relies on ontology and relationship, to a subjective perspective that analyzes act and function as relatively independent from any metaphysical essence and purpose of the creature. Relationships and purposes may even be thought to be unchallenged presuppositions, and therefore should be discarded for a truly proper interpretation of a creature or action. From this perspective it is more difficult to make inferences and draw implications. So just because semen is emitted, and one is sexually aroused, and emotional attachment deepens in sexual relations doesn't mean that these cannot be sharply distinguished or even separated when it comes to consideration of the integrity of the act or the complementarity of the aspects. Thus one would also be in greater need of explicit commands or passages from whatever one's authority is (in this case, the Scriptures) for determining the integrity of the act and what is allowed or prohibited.
So I suspect that you are at an impasse until you address this epistemological difference. Most people don't think the way Dr. Heidenreich is arguing, which I think was his point in the first place.
Secondly, consider this comment last night by Rev. Robert C. Baker in a discussion here on L & P:
...at the turn of the last century many Christians were divided over the issue of evolution, the purpose, role, and authority of Scripture, etc.
The world was changing. Because believers also use the language of the world, which brings with it ideas and concepts foreign to the faith, they begin to reflect and write on their faith in a different way. Some believers followed after the Princeton theologians and accepted Fundamentalism. Others, following Kant and Schleiermacher, accepted Liberalism. When you are accused of being a Fundamentalist, or a literalist, or a traditionalist, for example, most likely the person making such an exaggeration is operating from a Liberal set of beliefs, whether or not he or she is aware of it.
In addition to Fundamentalism, another reaction to Liberalism came through the teaching of Swiss Reformed theologian, Karl Barth. Barth denied natural law and taught a strong divine command theory ethic, which means that the only commands that are valid for the Christian are those that are recorded verbatim in Scripture. If you cannot find a Bible verse specifically condemning any activity, then you are free to do that activity.
I find this line of reasoning being utilized, with no apparent credit to Barth, by Missouri Synod theologians beginning in the 1930's, about the same time as when Barth was having his famous debate with Emil Brunner.
The strong divine command theory ethic is why, in my opinion, that modern Lutherans accept contraception (because it is not specifically condemned in Scripture), whereas orthodox Lutherans (Luther, Melanchthon, Chemnitz, Gerhard, et. al.) condemned it as violating the first, fourth, fifth, and six commandments. This method is also why "conservative" Lutherans are unable successfully to address current moral crises today. To wit, most current condemnations of the ELCA's decision to allow same-sex unions and the ordination of gays and lesbians highlight that these are condemned in Scripture.
True, but same-sex attraction and activity also violates the moral law embedded in human nature. Even without Scripture, these folks should know better. If you don't believe me, ask St. Paul.
For more about my views, log on to bioethike.com.
Robert C. Baker