More on Catholic Sexual Morality: The Natural Function Argument

Consider the right-making feature on the Catholic view. Arguably, I misstated it in the column. Here is a statement of the Catholic view from a site on catechisms. 

http://www.catechism.cc/articles/QA.htm#05. 

In order to be moral, each and every sexual act must be marital and unitive and procreative. This is the threefold object of every moral sexual act. This natural sexual act is procreative precisely because it is inherently directed toward procreation. In other words, it is the type of act that is intrinsically ordered toward the good end of creating new life. But even when this act does not or cannot achieve this good end (its moral object), the act remains inherently ordered toward that same end, and so it retains that good, the procreative meaning, in its moral object. An act does not have to achieve its moral object to be inherently ordered toward its moral object.

There are, as far as I can tell, three possible explanations of what makes a sex act between infertile or no longer fertile couples inherently ordered toward procreation. 

1. Attitude. The sex act is inherently ordered toward procreation because couple has some attitude toward conception.   

2. Possibility. The sex act is inherently ordered toward procreation because  it is possible that the sex act cause conception. Perhaps this should be interpreted as metaphysical possibility given the couple's physiological makeup. 

3. Act-Type. The sex act is inherently ordered toward procreation because the act-type is such that it can, in others, cause conception. 

I should have mentioned option (3). This is likely closest to what the doctrine is, although other parts of the Catholic doctrine suggest that it is (1). This can be seen in the overlap with the doctrine of double effect and its relation to sex. 

Is the missionary position the only moral sexual position?

No. Any sexual position of natural genital-to-genital intercourse between a husband and wife thereby retains the marital, unitive, and procreative meanings, and so would have a good moral object. But to be moral, each and every knowingly chosen act, in addition to having a good moral object, must also have good intention, and the good consequences must outweigh any bad consequences.

(3) is implausible because the inherent rightness of one act should not depend on the features of other acts.  

The smaller problem I have with (3) is that it begs the question. There has to be some feature of it that makes non-marital-and-vaginal sex wrong in the standard cases. Here I suspect it has to be either the attitude (1) or the possibility of conception (2) and so (3) would have to be filled out via (1) and (2). 

In any case, I should have mentioned (3). 

The principle that best fits and justifies these rules is something like a positive attitude toward new life, metaphysical openness to reproduction, or, perhaps, a view of organs as having a natural function. I think this because the difference between man-made and natural ways of preventing pregnancy would not explain why bestiality and masturbation are grave sins. My guess is that there is a unified explanation as to why they and using contraception are sinful. 

Perhaps the natural function view of organs does the justificatory work, but it is mysterious how an organ can have a function other than God's design and evolution. 

Note this is written in response to some extremely helpful comments by Ray Belliotti.