We know how Mitt Romney feels about marijuana. But what about caffeine? A.P. notes that he "joins other observant Mormons in shunning alcohol and coffee," although he does eat coffee ice cream. His wife, Ann, says he drinks "caffeine-free Diet Coke." Is that a Mormon thing too? This week the Church of Jesus Christ of Latter-day Saints weighed in on that question with a "small correction" to an NBC report that claimed caffeine is forbidden to Mormons:

Despite what was reported, the Church revelation spelling out health practices (Doctrine and Covenants 89) does not mention the use of caffeine. The Church’s health guidelines prohibit alcoholic drinks, smoking or chewing of tobacco, and "hot drinks"—taught by Church leaders to refer specifically to tea and coffee.*

That asterisk refers to a footnote that says "this posting has been updated since it was orginally published." Updated how? The Fox station in Salt Lake City reports that the post originally ended with the sentence, "The restriction does not go beyond this." So while the church initially seemed to have settled the caffeine question once and for all, saying the drug is permissible as long as it is not consumed in the form of tea or coffee, it opted instead to leave the dispute unresolved.

Although the caffeine controversy may seem of little interest to non-Mormons, it sheds light on the evolution of drug taboos, which is why I discuss it in my book Saying Yes: In Defense of Drug Use. The textual source for these prohibitions is the Word of Wisdom, as recorded on Section 89 of the Mormons' Doctrine and Covenants:

Inasmuch as any man drinketh wine or strong drink among you, behold it is not good, neither meet in the sight of your Father, only in assembling yourselves together to offer up your sacraments before him.

And, behold, this should be wine, yea, pure wine of the grape of the vine, of your own make.

And, again, strong drinks are not for the belly, but for the washing of your bodies.

And again, tobacco is not for the body, neither for the belly, and is not good for man, but is an herb for bruises and all sick cattle, to be used with judgment and skill.

And again, hot drinks are not for the body or belly.

By reading "hot drinks" to include tea and coffee but not, say, hot cider, LDS leaders imply that caffeine is the issue (which makes sense, since the other things forbidden in this passage also contain psychoactive substances). If so, coffee is forbidden even when you put it on ice. But then what about soft drinks that also contain caffeine? Judging from the editing of this week's blog post, church officials themselves disagree about the answer.

It might clarify things to know the moral principle underlying the Word of Wisdom. The church teaches that "the message of the Word of Wisdom is to avoid all substances that are harmful to our bodies," and "drugs are harmful when used outside of specific medicinal purposes." According to a statement issued in 1974, "The Church has consistently opposed the improper and harmful use of drugs or similar substances under circumstances which would result in addiction, physical or mental impairment, or in lowering moral standards."

The "medicinal purposes" exception allows the use of psychoactive substances when they are prescribed by a doctor, and it is perhaps telling that Utah, full of teetotaling Mormons, leads the nation in the use of antidepressants. Leaving that issue aside, we now have a standard by which to judge the propriety of using a drug: Is it "harmful to our bodies"? The permissibility of caffeine becomes an empirical question: Does moderate consumption of this stimulant lead to addiction, physical or mental impairment, or immoral behavior? If so, caffiene should be prohibited in every form. But if not, why are coffee and tea prohibited? You can begin to see why the church is leery of taking a definitive stand on this issue.

The Mormon ban on coffee and tea, of course, is not legally enforceable, but many other, equally arbitrary drug preferences are. So as trivial as it may seem, Romney's reasons for drinking caffeine-free Coke may actually be relevant to his reasons for supporting the ban on marijuana and other politically disfavored intoxicants. Even if caffeine avoidance is not a moral issue for him, abstaining from alcohol and tobacco presumably are. If so, why is he willing to let other people make different choices? Why doesn't the same logic apply to other drugs as well? Romney may have answers to those questions that hinge on the specific hazards posed by the drugs that happen to be illegal. But I doubt it.