WARNING: SOME DELICATE MATERIAL IN THIS POST!
Zoe,
Let me tweak something you said:
COrrect me if I am wrong...but the essence of an accidental property is that is could be slightly different and not affect the inherent purpose.
Note the underlined words. That's very close, but just a little off. It is very close in that it can be right in many ways, but off in that it misses an important nuance. Change those words to
not affect what it basically is and you have a better statement.
A wood, metal, and plastic chair are all chairs. A bald man and a man with hair are both men. Red, blonde, and brunette hair is all hair. Thus. wood, metal, plastic, baldness, and haircolor are all accidental properties. Against this would be the essential property of the thing--that is, the property that is part of the thing's essence.
Look at it this way: if you take away or change some aspect of a thing, is the thing still what it was before? If not, you have an essential property. If so, you have an accidental property.
Applying this to sex, there are some things that are obvious. If you take away one person but leave the biological conclusion (as in masturbation), do you still have sex? Obviously not, so we see that two individuals are required for sex (this, by the way, would form a basis for a philosophical argument against polygamy, but we'll save that for another thread).
Now, let's get a bit more controversial and try to be as polite as we can. What if the same act we call masturbation that we decided was not sex is now done with two people? Suppose rather than a person doing that to themselves, someone else does that to them? Is that sex? Before you jump to an answer either way, imagine a virgin girl engages in that activity. Would she still be a virgin? I think so, therefore, I'm forced to conclude this act is not sex. Now let's change the situation so that instead of dealing with hands, we are dealing with mouths. By the same logic, we still don't have have sex proper (again, unless you believe that such an act results in a person losing their virginity). So it seems that not only must there be two people involved, but those two people's genitals must be involved.
Before we go any further, let me deal with an unnecessary "Christian" objection. Some may complain that if I say these acts are not really sex, then I am endorsing them, or saying, in some sense, that they are OK to practice outside of marriage. I AM NOT. At the end of this, when I deal with privations, I will show why.
The interesting thing about the conclusion about the above paragraph is we see that even "gay sex" doesn't
really exist. What gay couples do (on either side) is absolutely just the same as what naughty teenagers two when they don't want to actually have sex. By itself, this provides an argument against the existence of gay marriage. But now we are getting ahead of ourselves.
So the essence of sex is the biological union (through the genitals) of a man and a woman. It is exactly here that procreation comes in. What is the purpose of the male and female sexual organs? Do they exist not for the express purpose of creating children? Unless you are going to argue that human sexual organs and those of most of the animal kingdom are essentially different--such that they don't even have the same thing we have and vice versa--it is absolutely evident by all of nature that the very reason those organs exist is for procreation.
Thus, we see that the primary purpose for sex in procreation.
NOW - does that mean that there are no other sub-purposes? Does that mean that the fact that sex is enjoyable or brings you closer to your partner or a myriad of other things mean that those things are NOT important? OF COURSE NOT. Do not confuse accidental properties with non-important properties. I happen to find the taste of food very important. In fact, it is the accidental properties of things that provide 99% of the context for our lives. Jesus Christ used the accidental properties of things to explain the Kingdom of Heaven. I am NOT saying accidental properties are a take-it-or-leave-it kind of thing. Any car salesman who has ever lost a sale because he didn't have a red, rather than blue, car on the lost can tell you that accidental properties are important. But it would be absurd to say that just because he didn't have the red car, he didn't have a car.
Note, again, that just because any particular male/female sexual encounter doesn't result in children (whether it is because it just didn't happen that time or because one of them is incapable for whatever reason) doesn't mean that what they have experienced is not sex in the proper sense of the word. It just means it didn't happen that time. Whether or not there are physical barriers that keep their organs from accomplishing their intended purpose is not the issue.
As a final note, what about those other "sex acts"? Are they OK? I'll leave it to each married couple to decide what is or is not OK within the bounds of their marriage, but I think it is evident that no such act is OK outside of those bounds. The reason is that all such acts are derivatives of sex itself. That is, these acts have taken sex and taken away its essential property and yet maintained one of the accidents--yet the accidents derive directly and completely from the essence of the act itself. If sex is to be within marriage, and I think we all agree it is, then it follows that that which comes from sex or is derived from it ought to be within the bounds of marriage. Our culture has it backwards. These sex acts do not precede sex--they come after it, in the logical sense. If sex itself didn't exist, then those acts would not, just as if eyes did not exist then neither would blindness. Just as blindness is a privation of sight, so these sex acts require a privation of sex itself.
Sorry for the length, I hope that helps clear things up.