Originally Posted by Smokering
Bluegoat: I found the bit about unity and procreation in Humanae Vitae:
It's pretty much what I was led to expect by this thread, down to the implication that in sex involving ABC the "sense of true mutual love" is somehow broken - which is not defended, just handwaved to "human reason". It also seems strangely to imply that "natural" sex always renders a couple capable of "generating new life", even when it made the point several chapters previously that this was not the case.
You probably need to look at "Theology of the Body" I would say.
To sum it up in one sentence, I would say - "All natural truths are also theological truths." I'll also say that it is not a work that will be easily understood from a position which says every philosophical argument can be reduced to a syllogism. It has I think a more Augustinian or PLatonic character.
The trouble with formal logic is that it is very limited in how it can be used in discussions of any real import. Not because reason is limited (although there is a kind of truth to that) but because we are, and human reason is. Which is why Plato and even Aristotle use not formal logic, but dialectic as the highest form or argumentation in philosophy, and I think why 20th century philosophy has been so limited in scope - it admits only syllogisms which soon become nothing more than word-play.
God, we know is perfect unity. Many things are true according to God's reason which are beyond the reach of human logic - the Trinity is a good example. You cannot show mathematically how three can be one, and it seems to contradict the law of non-contradiction, even if you delve into what substance is, or persons, and other obscure theological issues.
That doesn't mean that we must abandon reason, or that the Church simply makes things up by some inspired guess. Philosophy and theology have other methods, and in theology Tradition and Scripture provide a guide. And these methods are not just available to those who make the decisions in the Magestirium, but to all Christians. They do, however, take more time and work than simple use of reason.
I mentioned dialectic, which is one very worthwhile tool. As well, the Augustinian method, which involves the exploration of the inner world, the microcosm, as well as the outer world. As he points out, we see the macrocosm externally, and we must "figure out" what natural laws are moving it. In the case of our own bodies and souls, we have extra insight.
THe pagan neoplatonic philosophers developed these things into a real method, and Christians refined it to fit Christian understanding. In order to attain the highest knowledge of God, we must first train our bodies and minds through habit. Good living, and even fasting, and prayer. Then there is reason - we are required to study. But to attain a real first-hand knowledge, we go beyond that even to a mystic unity, and this is accomplished through unceasing prayer, and then God brings us to that experience of unity. Some Christian saints became talented at this, but many people never achieve it. Among the pagans, even Plotinus only experienced it a few times.
What does this mean concretely for those trying to understand theology? It isn't simply a matter of following some "rules" of logic. First of all, they can be warped by our tendency to concupiscence, and secondly they are not adequate to God's reason. So when we try to read something like "theology of the Body" we don't just look at its logic. We have to hold it in our minds and try to look at the world through that lens, maybe even live it (we are after all whole people, not minds stuck in foreign bodies). We need to disciple ourselves to it before we are in a position to accept or reject it. (In fact this is true of any comprehensive worldview - which is why philosophy takes imagination.)
I this case, I think "what is natural law" is the subject. What does it mean that the universe works a certain way, that each thing operates according to its logos? What does it mean to try and change the nature of that through technology, which has a logos of its own? Can our capacity for embracing untruth infect such attempts?