The Church's teaching on sexuality that lies behind its teaching that contraception is intrinsically immoral is so dazzlingly beautiful that many people whose understanding has been clouded by the corruption of our culture have difficulty understanding it.

The Church understands sexuality to be an inestimable gift from God; one that allows a man and a woman in a very personal, profound, spiritual and physical way, to express their deep desire to unite with another and to live out the essential human need to love and be loved. God himself is a lover and, in fact, is Love Itself. Love is a union, and the sexual union of spouses allows them to more fully actualize the love between them that unites them. Furthermore, it is natural for love to overflow. In fact, all of creation is the result of the natural overflowing of God's love. The Trinity has no need of "others"; they are three perfect persons who love each other perfectly, but they "naturally" explode with love and that love "naturally" leads to new life and new possibilities for love. Thus the whole universe is fueled by love.

'Co-creators' with God

Spouses are meant to image the love of God; they are meant to be committed unconditional lovers whose love overflows into new life. Pope John Paul II spoke of spouses as being "co-creators" with God; they assist God in bringing forth new human souls.

Spouses who truly appreciate the gift of fertility understand that when they are not prepared to accept the gift of a child, they should abstain from sex when a pregnancy is possible -- that is, they use natural family planning (NFP). NFP is a way of respecting the great gift of fertility. Many studies and testimonies affirm the benefits of using NFP. The U.S. bishops issued a very fine statement about the meaning of sexuality and the value of NFP in their 2006 document "Married Love and the Gift of Life."

Our culture is accustomed to thinking of sex as just a form of recreation that has no inherent, profound meaning. People rarely encounter the Church's teaching in its full glory, and when they do, they don't easily understand it. One method of helping people be open to the Church's teaching is to alert them to the bad consequences that contraception has for individuals, for the culture and even the environment.

Bad consequences

The case is easily made that contraception has greatly contributed to the increased incidence of abortion, unwed pregnancy, divorce and the poverty and trauma that comes with single motherhood. After all, contraception facilitates sex between partners who have no intention of having a baby.

All contraceptives have a failure rate, and people fail to use contraceptives even when available. Presently, about one out of four babies conceived in the United States is aborted, nearly 38 percent of babies are born to a single mother, approximately half of marriages contracted today are likely to end in divorce, and more than 80 percent of children who experience long-term poverty come from broken or unmarried families.

Who can calculate the harm done to babies born out of wedlock, to children impacted by divorce? The evidence is overwhelming that children born to parents who are married to each other, and who stay married to each other, have numerous advantages over children born out of wedlock or impacted by divorce. Who can calculate the harm done to individuals who are in and out of sexual relationships?

The biggest selling point of natural family planning should not be that it is as effective as any form of contraception or that it has no bad health side effects. Rather, we should be proclaiming from the rooftops that NFP is so good for a marriage that those who use NFP almost never divorce. Almost everyone who uses NFP has used contraception at some point and find that the use of NFP improves both their sexual relations and their marriage.

Chemistry project

Aside from the societal woes created by contraception, hormonal contraceptives have a negative effect on women's health and relationships between men and women. The health risks of chemical contraceptives have been known for a long time and range from weight gain to increased incidence of breast cancer and even death from blood clots.

More and more studies are showing the bad effect that contraceptives have on relationships. In my talk "Hormones R' Us" (see Resources link at www.mycatholicfaith.org) I report on some of the little-known effects of chemical contraceptives.

We often speak of the "chemistry" as being powerful between a male and a female who are strongly attracted to each other. The talk of "chemistry" is not an analogy; the attraction is truly based on chemical differences between males and females. Males and females exchange hormones called "pheromones" and these are the cause of the chemical attraction between them. These hormones are received through the olfactory nerves. Many women testify that the one of the things that most attract them to a man is the way that he "smells."

But hormones also affect our judgment and responses in other ways. What is important to note here is that women who are on chemical contraceptives have squashed the influence of their normal fertile hormones. Chemical contraceptives work by putting a woman in a state of pseudo-pregnancy. When pregnant, women don't ovulate. Researchers who invented the chemical contraceptives realized that they could "deceive" a woman's body into "thinking" that it is pregnant by giving it synthetic forms of the hormones that are present when a woman is pregnant. One problem with this scenario is that women respond to men differently when they are pregnant or on a chemical contraceptive than when they are not. And men respond to them differently.

Consider the T-shirt study report in the book "The Decline of Males," by Lionel Tiger. This study involved two groups of females, one that was on contraceptives and one that was not. It also involved a group of males who had been rated for their "evolutionary" desirability. The women, who never met the men, smelled the T-shirts, and on that basis identified which men they thought would make desirable mates. The non-contracepting females chose the evolutionarily desirable males; the contracepting females chose the losers!

The website nbc10.com has a fascinating video called "The Divorce Pill" that features research showing that women on the pill often choose to marry men who are not suitable spouses for them. This is of special concern since most women of child-bearing age in the United States use chemical contraceptives, especially during their years preceding marriage.

One amazing effect of the chemical contraceptives is that they reduce the amount of testosterone that a female produces -- and for females as well as males, testosterone is the source of sexual desire. Thus women on chemical contraceptives find their sexual desire is reduced and, possibly when they go off the chemical contraceptives, it may never return to the level it was before they began using chemical contraceptives.

So we have an interesting phenomenon: Women are choosing their mates not under the influence of their own more reliable fertile hormones but on alien synthetic hormones. When they go off the chemical contraceptives, they may find that they have a higher sex drive, but that they are not much interested in the man they are with!

Moreover, men produce more testosterone when they are around women who are having fertile cycles. One study showed that males who were in the presence of female fertile hormones found the pictures of ordinary women more attractive than pictures of super models.

Environmental woes

Contraceptives not only step all over relationships, they also leave a considerable carbon footprint. Consider that NFP has a zero carbon footprint: it burns nary a fossil fuel, whereas the amount of energy needed to produce, transport, distribute and dispose of contraceptives is astronomically high. Indeed, studies have suggested that divorce has a huge carbon footprint, since divorces generally doubles the need for housing, etc. Moreover, the estrogens in contraceptives have a lethal effect on some elements of the environment; they have been shown to destroy the fertility of some groups of fish, for instance.

Not only is the Church's teaching on contraception based on an understanding of sexuality that is sublime, it is also eco-friendly -- friendly to a woman's internal ecosystem, friendly to the "ecology" of the culture and of relationships, and friendly to the environment.

Janet Smith holds the Father Michael J. McGivney Chair of Life Ethics at Sacred Heart Major Seminary in Detroit.