So one of Gov. Sarah Palin’s best friends is gay. Her pal “happens to have made a choice that isn’t a choice that I have made,” Palin told Katie Couric last week. That language resurfaced in the vice presidential debate, when Palin insisted that she was “tolerant” of Americans “choosing relationships that they deem best for themselves.”

Calling homosexuality a choice is the time-tested way politicians signal their belief that it is the wrong choice. Which is why Palin’s comments prompted predictable anger from gay rights advocates. Typical was a Washington Post opinion piece saying that “no one would choose to be part of a marginalized group whose members have to sue their way to basic rights.”

But insisting that homosexuality is wholly involuntary does little to defend gays and lesbians from social disapproval. After all, the subtext of the “choice” debate is that opposing gay rights is only appropriate if gays select their sexuality, since it is unfair to punish someone for something one does not control. Yet this reasoning raises a larger question: Why should equal treatment of gays and lesbians hinge on whether they have chosen or inherited their identities? Whether our DNA or our free will are “at fault” really only matters if being gay is a bad thing.

It is past time to retire the question of whether being gay is a choice -- not because it’s been settled but because it never made sense in the first place. Indeed, when it comes to other aspects of our identity and behavior, we generally don’t dwell on the question of choice. To ask whether a practicing Catholic or a professional dancer has “chosen” to be a Catholic or a dancer seems bizarre, not because we entirely deny that an element of choice is involved but because we recognize that the lives we lead are the layered products of our experiences and passions, our convictions and longings, our judgments and follies.

What causes people to become vegetarians, athletes, poets, stockbrokers or bank robbers? Most people, if we bother to think about it, probably believe such identities are the result of responses to impulses and convictions that shape people’s actions over time. How the impulse or conviction got there, no one is certain, but there’s surely an element of chance involved. A person chooses to become a teacher, but the desire to teach and the conviction that says being a teacher is right and good -- these cannot sensibly be reduced to a simple act of human will.

Yet too many Americans continue to view sexual orientation as just that. At the same time, they cast other spheres of identity -- particularly religion -- as matters of unchosen conviction and deep principle. In fact, the parallels between sexual orientation and religious faith may be more marked than their differences. Religious Americans often speak of a surge of emotion from deep within them, of hearing a calling from something outside of themselves and of following the dictates of their conscience. Likewise, gays and lesbians frequently describe same-sex attractions as an undeniable force or a deep-seated feeling that they must respect if they are to be true to themselves.

How one responds to these stirrings may be largely a matter of choice, just as one may choose whether to act on a belief or whether to practice a faith. But American institutions properly protect our right to practice the religion that speaks to our soul. Why not champion a homosexual’s right to honor erotic, romantic and emotional callings in the same way, so long as doing so doesn’t harm others? The concept of choice should be no more -- and no less -- applied to sexual orientation than to our religious, political or vocational identities.

It is this understanding of choice that embodies the noblest meaning of American freedom. It is a conception of freedom that invites us to choose to do what we think we ought -- to act in accordance with our deepest convictions.

And it’s a notion of freedom with a long and celebrated history in American culture. The Pilgrims did not come to America seeking license -- permission to do anything they pleased -- but liberty -- the right to exercise their judgment as they saw fit. The freedom celebrated by Thomas Jefferson was the freedom to practice civic virtue, to behave the way one thought one should, not to live and let live. Ralph Waldo Emerson counseled self-reliance -- not so we could indulge our whims but so we could intuit our true callings and choose to pursue the paths that made us most ourselves.

If Palin’s gay friend is like other gays and lesbians, her sexual orientation is neither a choice to be tolerated nor a sentence to be served. It’s an expression of her freedom to be herself, a freedom that, as Palin said in the debate, “is always just one generation away from extinction.”

Nathaniel Frank, senior research fellow at the Palm Center, is the author of the forthcoming “Unfriendly Fire: How the Gay Ban Undermines the Military and Weakens America.”