People often surmise that same-sex attraction is inborn, and that homosexuals are "naturally gay" or "born that way." They suppose that if God made them that way then it must not be a sin to act on their sexual desires. The possibility of a "gay gene" is sometimes offered as a further defense, suggesting that the condition, and its associated behavior, are inevitable and inescapable. One commentator summarized it this way: "Asking someone to stop being homosexual would therefore be equivalent to asking an Asian person to stop being Asian or a left-handed person to stop being left-handed."

Even if a hypothetical "gay gene" were ever found, all it would likely determine, similar to most genes governing behavior, would be a genetic predisposition towards a particular sexual preference. This would be something very different from the genetic determinism or "hard-wiring" of, say, eye color or blood type. Multiple twin studies have already demonstrated that only about a third of the identical twins of those with same-sex attractions also experience same-sex attractions; whereas if sexual attractions were determined strictly by genes, those with identical genes would be expected to have identical attractions.

Even if we have genes that predispose us towards certain behaviors, we still have a space of freedom within ourselves, and do not have to engage in those behaviors. Our genes may impel us strongly in certain behavioral directions, but they can't compel us.

This reminds us of one of the fundamental truths about our human nature ? namely, that we are not creatures of sexual necessity. We are not compelled to act on our inclinations and urges, but are always free to act otherwise, even directly against the grain of those inclinations. In fact, to be truly free as a human means to have the strength to act against ourselves, so that we do not live in bondage to our own inner impulses and drives, a key consideration that distinguishes us from the animals. Human freedom involves the mastery of those drives by redirecting them and ordering them to higher goals. So while we cannot in any way be held responsible for in-born inclinations, we certainly can be held responsible for how we choose to act in the face of those inclinations.

Sherif Gergis summarizes this idea in a recent article: "We do not pretend to know the genesis of same sex attraction, but we consider it ultimately irrelevant to this debate. On this point, we agree with same sex marriage advocate Professor John Corvino: 'The fact is that there are plenty of genetically influenced traits that are nevertheless undesirable. Alcoholism may have a genetic basis, but it doesn't follow that alcoholics ought to drink excessively. Some people may have a genetic predisposition to violence, but they have no more right to attack their neighbors than anyone else. Persons with such tendencies cannot say 'God made me this way' as an excuse for acting on their dispositions.'"

Even though God did make each of us in a certain way, it is clear there are other factors that have influence over our personal constitution and inclinations as well, including actual sin and original sin. It is not difficult for us to see, through the turmoil of our own disordered inclinations, how our human condition, our general biology, our psychological depths, and even our DNA, seem to be subject to a fundamental fallenness.

It would not be unexpected or surprising, then, if we eventually discovered predisposing factors (genes, hormones, developmental cues, etc.) that give rise to heterosexual or homosexual inclinations. What is of real moral relevance to the discussion, however, is the universal call to chastity, irrespective of genes and hormones.

Chastity refers to the successful integration of sexuality within the person, and all men and women are called to live chastely in keeping with their particular states of life.

Some will do so by professing a life of consecrated virginity or consecrated celibacy.

Married people will do so by living conjugal chastity, in the exclusive and lifelong gift of husband and wife to each other, avoiding the unchastity of contraceptive sex, and sharing the marital embrace in openness to new life. Professor Robert George speaks of "marriage as a union that takes its distinctive character from being founded, unlike other friendships, on bodily unity of the kind that sometimes generates new life."

Those who are single will practice chastity in continence, steering away from fornication, masturbation, and pornographic pursuits.

Those who experience an exclusive or predominant sexual attraction toward persons of the same sex are similarly called to chastity in continence. By refraining from sexual activity with members of the same sex, and engaging in an apprenticeship of self-mastery, they come to acquire, like all who pursue lives of chastity, an abiding inner freedom and peace.

Rev. Tadeusz Pacholczyk, Ph.D. earned his doctorate in neuroscience from Yale and did post-doctoral work at Harvard. He is a priest of the diocese of Fall River, MA, and serves as the Director of Education at The National Catholic Bioethics Center in Philadelphia. See www.ncbcenter.org.