A methodology of deriving an ethical decision from Nature is illustrated by St Paul in Romans 1:26-27. Here he accuses both women and men of exchanging natural functioning for unnnatural, and it is clear from this case that both “natural” and “unnatural” have ethical value. The irony here is that our modern understanding of Nature has differed from Paul’s understanding of Nature. So when we adopt the same methodology, we end up with opposite conclusions.
In summary, there are three things which appear to be determined by Nature in human beings: sexual orientation, sexual structure, and sexual identity.
In regard to sexual orientation, approximately 2% of a human population appear to be exclusively homosexual in orientation, 18% bi-sexual, and 80% exclusively heterosexual. While the determination of sexual orientation appears to have continuity with the animal kingdom, its determination as natural is not determined by that continuity, but by its occurrence in humans.
Sexual structure in humans is also determined by Nature. When a child is born we might expect it to be called out, “It’s a boy! It’a a girl!”. But sometimes it is not so clear. Children can be born with confused genitalia and obviously, they have no say in it.
Sexual identity also appears to be biologically determined. The problems occur when someone with the sexual structure of one human gender appears to have a discordant sense of sexual identity. This can be very tricky. So let’s not get caught up arguing about the third case so much that it blinds us to understanding the situation of the previous two.
With regard to ethical choices we make in the light of Nature, we are not thinking about birdnests, but about what Nature determines for humans.
It can be seen from even Scripture, that Sola Scriptura does not hold up, as illustrated by Romans 1. Sola Scripture may have been the war cry of Martin Luther, but it becomes obvious that Luther’s doctrine was simply setting his interpretation of Scripture against the Roman Patriarchy’s interpretation of Scripture.
In retrospect, Luther was simply a child of his time. His emphasis on salvation by grace through faith was and is certainly true, but it does not cover the fullness of the Christian Faith. Even in those Scriptures, the apostle reached out to Nature. Furthermore, the Christian Faith does not replace one form of legalism with another form of legalism, but relies on the Holy Spirit to lead us into new insights in the light of science. Unfortunately, this moves us into another situation of difficulty.