This is what I sent to the NR in response to a staff essay accusing Howard Dean of being in favor of incest.
Excuse me, but I did think the people working for the National Review had a working knowledge of logic.
The word "incest" refers to sexual intercourse between two biologically close individuals. Whether such behavior is permitted or forbidden by social regulations has no effect on its nature.
Marriage, on the other hand is a contract between two individuals that is deemed to be worthy of recognition by others in the community, regardless of whether this contract is supported by, reinforced by or even involves sexual intercourse. While it used to be not uncommon for one party to such a contract to argue that it had been unilaterally voided or violated by one of the parties failing to participate in sexual acts, such acts are not a necessary component.
In other words, while incestual sexual relations do not depend on a legal determination or definition, a marriage contract definitely does because its very essence is to seek validation by a third party (society) of an agreement that two people have entered into.
While there are, no doubt, some people who would like to think that there is a strict relationship between a marriage contract and sexual intercourse and that this very private behavior can be regulated by society passing laws, the fact is that it just aint so.
For the record, just as marriage contracts or civil unions have no direct effect on sexual behaviors such as soddomy or oral genital stimulation (neither to promote or inhibit) a contractual relationship of mutual care and support between biologically related individuals says nothing about their sexual contacts. Which is probably why Howard Dean voted to support a Republican bill that recognized this reality.
The reason I am even bothering to address your illogical essay is because it has become quite common to attempt to prevent one kind of behavior by prohibiting another that is only indirectly related. For example, in the interest of preventing the subcutaneous injection of some drugs (illegal because declared by legislation to be so), the sale of disposable syringes for uses other than by prescription has been declared illegal, making it very difficult for diabetics to maintain an adequate supply and increasing their cost significantly and making it more likely that they will be stolen. Also, based on the premise that the consumption of alcohol makes young drivers even more accident prone than their elders, the consumption of alcohol by all people under the age of 21 has been declared illegal when, from a societal perspective, it would make much more sense not to issue driver's licenses or register automobiles for people under the age of 21 or to people whose consumption of alcohol has been proven to make them bad drivers.
In each instance individual rights are restricted because society as a whole is reluctant to make the necessary structural improvements to promote appropriate behavior.
How you reconcile "political and social moderation" with the restricting of individual rights is beyond me.