I’ve often said that atheists have a penchant for redefining terms. The most frequent use of this tactic is seen by redefining “faith” to mean “belief without supporting evidence.” Faith is trust, no more and no less. It’s repugnant to see former believers continuing that redefinition, even though they know better.

But atheists, by their own reckoning, are also free to not only redefine established terms but also free to redefine morality. This is because they are no longer “shackled to a Bronze Age mythological belief system.” The comments to this post from Daniel Florien serve to show just how far this can be stretched.

I can see a god – if such a creature could be called ‘god’ – who would demand certain behaviors; but that does not mean it’s worthy of worship. And frankly, the only behavior I’d absolutely, in every circumstance, consider immoral is rape and cheating, because those actively involve hurting another person (though, frankly, I don’t think cheating’s all that terrible either, as to be ‘immoral’ – simply because I’m not – personally – convinced monogamy is all that special. I’d say cheating is immoral much like lying is immoral – and only as far as that). I don’t consider incest particularly immoral in a time where birth control is relatively easy, given consent from both parties (see: not rape).

First of all, that God demands certain behaviors is not what makes him worthy of worship. Why God is worthy of worship can be discussed some other time. More troubling, however, is this comment’s declaration that the only behavior considered immoral in every circumstance is rape and adultery. Then, the commenter goes on to negate the previous statement by saying that adultery may not be that wrong after all.

This is what happens when humans stop allowing God to define the terms of his gifts to us. Our sexuality is a gift from God, and it is used to unite couples and procreate children to continue the human race. Since God has created this gift, it is his to define. There are plenty of rules given for sex in the Bible, but the main thing to take away from all of those rules is that the only sex that is morally praiseworthy is that which takes place within a marriage. The fact that there are rules for sex at all demonstrate the high regard God holds it in. By defining it this carefully, he intends for us to get the maximum enjoyment from it. It is not God’s goal to repress our sexuality, as many Bible critics contend. Again, we can make a whole other post on this topic–that isn’t the point I’m trying to make here.

As to the commenter’s position on incest, I can’t imagine anything more morally depraved. Where does it stop? What if my son and daughter get older and curious and decide to play “doctor?” Is that fine in the commenter’s mind, given that they can simply use bith control to prevent potential offspring?

But I’m simply arguing from outrage here, which is a tactic I frequently accuse skeptics and atheists of doing when they argue against the Old Testament Law. What about some hard facts from the experts to back up my underlying claim that incest is damaging? Well, let’s start with a February article from CNN.com. Here, actress Mackenzie Phillips retracts a statement made in her autobiography that her incestuous relationship with her father was consensual. The experts consulted for background on this article agree that incest is never consensual. It can’t be by definition.

Incest leads to numerous problems: confused sexual identity, drug and alcohol abuse, harboring resentment for your abuser. None of these things are good over the long term.

Further, birth control isn’t 100% effective. Even used properly, any form of birth control can still fail and lead to a baby. None of the commenter’s points seem to be valid.

Now, the skeptics will parade out the usual objections to this line of reasoning, most likely noting that the Bible contains examples of incestuous relationships (e.g. Jacob marrying his sister-in-law). To which I preemptively reply that describing something as it is is not necessarily condoning it. The Bible is a very graphic book, and describes some horrible things, but it is still very clear about what God condones and abhors. Describing a situation, like an incestuous relationship, is simply describing the situation as it stands. It is not condoning it. The Bible condemns many incestuous relationships specifically in Leviticus 18:1-30 and Deuteronomy 22:13-30.

Another commenter is almost right:

I believe adultery is wrong, regardless of god’s existence, in most cases. Some couples successfully have an “open marriage” but this is rare in both the gay and straight communities. Usually jealously and drama ensues when partners swap out regularly. If your partner is NOT into open marriage, and you cheat, its definitely wrong IMHO, because of the massive emotional pain and suffering you inflict on them, the children if there any and so forth.

So as long as both partners are into the adultery, it’s fine. But if one isn’t, then the other should remain faithful, otherwise it will cause emotional harm. This reminds me of the Wiccan Rede: “An ye harm none, do as ye will.” This is a terrible philosophy, because it essentially leaves the definition of “harm” and “none” in the hands of the individual.

Unlike the Bible, which defines its morality at great length, the Rede leaves a lot of room for interpretation. And that is basically what our commenter is doing.

Someone eventually states that incest is morally wrong, and we hear this from yet another commenter:

No incest? Why is incest morally reprobable?

If we learn nothing else from the Bible, we should at least learn that mankind is enslaved to sin (Rom 7:7-25, 8:10; Eph 2:1), and will go to great lengths to justify it (Jn 3:19). Eventually, God will darken their hearts (Rom 1:21; Eph 4:18) and they will begin to believe that what they’re doing is right (2 The 2:11).

Incest has traditionally been defined as morally reprehensible by a vast majority of religious systems, and many secular legal systems (such as the United States) have followed suit. Sometimes the specifics differ (e.g. some states allow first cousins to marry, while most don’t).

The Bible is quite specific as to which relationships are forbidden, as noted in the verses above.

Why is incest wrong, apart from the Bible? Well, as we have previously noted, there is no such thing as consensual incest. There is a fair amount of agreement from the experts on that. Given the choice, most people don’t want to sleep with family memebers. In fact, the arcticle linked above says that children raised in close proximity to each other (such as brothers and sisters; maybe you can stretch that to cousins to a lesser degree) have a dampened sexual desire for one another. In other words, they don’t want each other sexually.

Further, incestuous relationships bring weak genes to the forefront in the resultant offspring. I assume that this is why the commenters bring up modern birth control methods, which are much more effective in preventing pregnancy than anything that was used at the time that the Bible was written. But, these measures still aren’t 100% effective. Offspring could still result from the coupling.

So, what? If a baby results from the coupling of a “consensual” incestuous relationship, that leaves us with little choice but to abort the baby. But that is a really harsh thing to do. The child didn’t ask for that, and should still have a right to life.

The best way to handle all of this is to continue to enforce the old prohibitions on incest.

And, despite the fact that I know what I’m about to say is pure argument by outrage, and I am making no attempt to either disguise it nor justify it through some form of special pleading, I feel it must be said: Isn’t incest just gross?? Why would anyone want to have sex with their sister, cousin, or parent?