A book by Michael Philip Penn titled Kissing Christians is attracting attention. There is some tease in this earnest scholarly work, such as “Chapter One: Kissing Basics.” But, alas, there are only slight references to “eroticism.” Apparently the early Christian kiss was not erotic, even though the kissers interpreted the biblical command to “Greet one another with a holy kiss” to mean a kiss on the mouth.

Segue to the contemporary scene, where liturgical churches have retained or restored a mild version of this greeting in the form of the “passing of the peace.” When Roman Catholics were told to re-include this in their rites, they resisted. The late Dan Herr, a salty editor friend, told how, in response to the priestly command, he turned meekly to the woman behind him. Her arms akimbo, her face a scowl, she said, “I don’t go for that sh--.”

One would think the literal-minded Protestant churches would restore the greeting with a holy kiss, because the command is clearly and apostolically voiced or, rather, scriptured, a half dozen times in the New Testament. But literalism goes only so far.

Kissing Christians begins with a quotation from Clement of Alexandria: “There are those who do nothing but make the church resound with the kiss.” He worried about the “impure kiss, full of poison, feigning holiness.” Penn admits that his discovery that “early Christian men and women kissed each other on the lips forced [him] to reevaluate [his] image of the ancient church.” He assiduously tracked the kiss, “one of the most prevalent features of early Christianity,” finding over 1,000 references to it in ancient writings.

Further, he found that kissing-on-the-mouth was encouraged among the faithful but discouraged with catechumens, visitors and outsiders, since—and this is his thesis—kissing was a boundary-setting act. Some people were ruled out by kissing and some were ruled in.

The threat of eroticism, of course, remained, and in the second-century Athenagoras cautioned: “It is necessary to be careful of the kiss, or the salutation, because if our thoughts are the least bit stirred by it, it places us outside eternal life.” So we have to get it right.

I see problems and possibilities. In November I read the tragic story of a girl with a peanut allergy who died after kissing her boyfriend, who’d eaten a pea-nut butter sandwich. Should there be patting down of clothes, examination of purses, or Breathalyzer tests of entrants to church? Or shall we let trial lawyers salivate as they contemplate suing churches which were not peanut-free?

I also read that the television show Desperate Housewives is being prepared for Spanish-speaking audiences and the soundtrack is being lip-synched by professionals. There is much kissing in the show, and evidently Spanish kissing sounds different from non-Spanish kissing, and the kissers have to practice a lot. To save each other’s lips they kiss their own hands, evidently producing a satisfying sonic equivalent. In liturgical rites, should there be an option of passing the peace by kissing our own hands?

Penn cites historian L. Edward Phillips, who found three types of kisses mentioned in the early church: osculum, a ceremonial kiss of friendship; basium, a kiss of affection on the lips; and suavium, a lover’s kiss which involved the tongue. Penn himself studied thousands of examples in Roman art and could find only six depictions of nonerotic kisses, with very few early Christian references to erotic ones.

Now that literalists have been reminded of the scriptural command, they must start kissing. Meanwhile, moderates and liberals will compromise with wan but—I contend—still meaningful handshakes or embraces of peace.