7. You shall not commit adultery.

Index Value

Current Value: +0.96 lives per thousand people.

This index was last updated on December 15, 2003.

Graph

Methodology

Adultery refers to husbands and wives having sexual intercourse with someone other than their spouse. I'll use the convention here that sexual intercourse refers to the act of penetration, since that's what makes a baby.

Fornication refers to sexual intercourse by unmarried people. In the era when the Ten Commandments were given (1200 BC or so), people married at younger ages, so fornication was less of an obvious problem than adultery. I believe that fornication (pre-marital sex) should be included as an act contrary to the commandment against adultery, because sex before marriage runs contrary to God's blessing of sex for procreation and mutual affection within marriage. Fornication is adultery before the wedding.

The science fiction writer Robert Heinlein observed, "Everybody lies about sex." I do not think that Heinlein's observation is strictly true; nevertheless, it is difficult to obtain reliable data with regard to sex in general and adultery in particular.

For the Morality Index I would like to use as the negative component all acts of sexual intercourse that are not between a husband and wife. This definition would include adultery and fornication. This is a measurable quantity, but I don't think anyone is measuring it on an annual basis. Some surveys have been done on American sexuality, and the good surveys make an effort to separate the truth from what people will exaggerate or downplay about what they do.

The positive component of the seventh commandment should not be acts of sexual intercourse between a husband and wife. In a healthy marriage sex is good and proper, but it requires no moral effort. The positive component should be instances where someone was tempted to commit adultery or fornication, but decided not to do it. We want to measure situations where someone avoided adultery through an act of will and faithfulness to God's command. Here are some examples:

• The businessman on a trip who usually hires a prostitute, but this time decides to shape up his life and not have sex with a stranger.
• The woman executive who meets a former boyfriend, and decides not to sleep with him out of respect for her husband and children.
• The college student who says, "I could have gotten laid last night, and I wanted to, but I remember my Youth Pastor telling us to save ourselves for marriage."

I think this positive component is also measurable, but it would be even more difficult than the negative. I can remember particular instances from my own life where I resisted the temptation to have pre-marital sex. Can you? How about couples who have mutually decided to remain virgins until they are married? Should we count every date they go on, on the grounds that a different couple could have had sex that evening? Maybe.

Having said all that, I just don't think the data is available. Perhaps we could measure all the instances of extra-marital sex and avoided sex, but nobody is doing it now. Instead, I have chosen to use marriage as the positive component, and divorce as the negative component. This commandment is about the sanctity of marriage.

I'm aware that marriage is a natural and expected event in American society, and that it may not require a great moral effort. Nevertheless, a wedding does require a lot of effort, and the bride and groom do exchange vows publicly to remain faithful to each other. In American as of 2003 you don't have to get married; you can buy a house, live together, sleep together, and raise children without getting officially married. But marriage still represents the public commitment that a couple makes. Even if the husband and wife don't believe in God, their wedding still conforms to God's plan for marriage. Marriage is probably the best positive component of the seventh commandment that we are likely to get.

The Morality Index takes the position that marriage refers to the union of one man and one woman, since that is my understanding from the Old Testament. Same-sex unions are prohibited by Leviticus 18:22, Leviticus 20:13, and 1 Kings 14:24.

Divorce may not involve adultery; abuse, addiction, and abandonment will usually do the trick. Nevertheless, divorce represents the breaking of the commandment to cling together as husband and wife. For the Morality Index divorce is a sensible counterpart to marriage.

The Bible expects a man and a woman to remain married for as long as both shall live. There are instances in the Old Testament where a man has multiple wives. Modern Christians observe that Biblical polygamy always has problems, and partly for this reason polygamy is not permitted today. Remarriage after death of a spouse is no sin - the Morality Index counts only divorce of a living spouse.

The Old Testament advocates the death penalty in cases of adultery (Leviticus 20:10). This sentence was still in force during Jesus' time (see John 8:1-11, but note that the Pharisees let the guilty man get away!). The severe punishment for adultery suggests that adultery, and by extension divorce, should also be "worth" one life taken away. Divorce is pretty serious.

In Genesis 2:24 we read, "For this reason a man will leave his father and mother and be united to his wife, and they will become one flesh." The marriage union is called "one flesh", and this term almost seems to indicate that the union now has a life of its own. Divorce kills that life. Jesus quotes the Genesis passage in Mark 10:6, and adds, "So they are no longer two, but one. Therefore what God has joined together, let man not separate."

Anyone who has experienced divorce first-hand probably knows the wrenching emotions, the tearing apart of household and family. Divorce lawyers know the great strain that divorce places on children, and some lawyers try to bring about reconciliation on this basis and forget about their fees. In "Loss of a Spouse" support groups there is ongoing discussion about which is more stressful: to lose a spouse to death, or to divorce. Divorce wastes years of people's lives. The breaking of marriage really does have a high cost.

The Bible does not suggest any weighting scheme among the commandments, and the normal scenario is for each person to get married once during their lifetime. But should divorce really be "scored" as severely as homicide? I once knew a divorcing couple where the wife shot the estranged husband to death as he was removing his belongings from their house. Everyone who witnessed this tragedy would have much preferred a "peaceful" divorce over a murdered husband and his wife sentenced to many years in prison.

I have no wish to reduce the seriousness of divorce. Nor do I want to encourage any hint of capital punishment in cases of adultery, especially when Jesus chose not to do so. Therefore divorce will be "scored" as follows: divorce shall be "scored" as 0.2 lives for every person involved. A childless couple divorcing shall have a morality score of -0.4 lives. Children under 18 years of age shall also count as -0.2 lives, since they are adversely and severely affected by their parents' action. A divorcing couple with three children "contributes" -1.0 lives to the Morality Index, which is equivalent to one homicide.

The weight value 0.2 is not the result of a scientific analysis, but instead comes from a gut feeling on my part about the pain of divorce. To put it simply, 0.3 seemed too high and 0.1 seemed too low. The value of an index is not primarily in its accurate comparison with the outside world, but in its consistency across the months and years of its operation. I think most people would agree that a weight value of 0.2 lives per person involved in divorce is at least within the right order of magnitude. As long as we pick a weight value and stick to it, the index over time will be useful.

It follows that marriage shall have a morality score of +0.4 lives (+0.2 for each person involved, the man and the woman). I would also love to add +0.2 in those rare cases where there is an existing child of the sexual union, and celebrate with them that Mommy is getting married to Daddy! But I don't think I have the data.

Data Sources

Calculations

This section works through all the adjustments and calculations made, from the original datum through the final index value, so interested readers may follow and verify the methodology used. We will use the year 1946 because it represents an all-time peak in the marriage rate. (In 1946 many soldiers were coming home from World War II. I'll leave it up to the reader to figure out why Americans married and divorced in such great numbers during that time.)

Marriage

The source data from the National Vital Statistics Report is measured in marriages per thousand people. We normally expect each person to be married once in their lifetime. We then multiply by the weight value and the number of people involved in the marriage.

In 1946 there were 16.4 marriages per thousand people.

16.4 * 0.2 lives per person involved * 2 people involved = 6.56 lives per thousand people

Divorce

The source data from the National Vital Statistics Report is measured in divorces per thousand people. It takes one divorce to undo one marriage. We then multiply by the weight value and the number of people involved in the divorce. Until I obtain more accurate data, I will assume that each divorce on average involves one child of the marriage.

In 1946 there were 4.3 divorces per thousand people.

4.3 * 0.2 lives per person involved * 3 people involved = 2.58 lives per thousand people

Composite Index

We add the marriage and divorce rates together to get the final composite index.

1946 Morality Index for Commandment 7 = 1946 Marriage Index - 1946 Divorce Index
= 6.56 - 2.58 = +3.98 lives per thousand people

The table below contains the final index values for the Seventh Commandment.