Our society is increasingly sensitive to the ways in which hateful speech can lead to violent actions or discrimination against people based on skin color, religion, gender, sexual orientation, or national background. This is a good thing: we all have a moral obligation to be courteous and respectful in the way we talk to and about each other. In speech as in all other actions, we should treat others as we wish to be treated. Moreover, hateful stereotypes can indeed foment discrimination or even violence (witness the Matthew Shepard tragedy).

However, the category of impermissible speech seems to be widening all the time, and this can pose some problems for freedom of speech and inquiry. Consider some examples. The mother of Tyler Clementi, the gay Rutgers student who took his own life after being secretly filmed in an intimate act with a man, has recently left her evangelical Christian church because that church teaches that homosexual acts are morally wrong. She now believes that such teaching helps to create the homophobia that drove her son to suicide. In Canada, where hate speech is illegal, some Christian pastors have been prosecuted merely for condemning homosexual activity from the pulpit. Some Christian theologians, seeking to overcome centuries of Christian anti-Semitism, have called for Christian churches to stop teaching that Jews ought to convert to Christianity or that Christianity has replaced or superseded Judaism as a religion. Many people today who criticize Islam are attacked as Islamophobes, since a negative opinion of Islam could lead to discrimination against Muslims. Pro-life activists are sometimes blamed for attacks on abortion clinics or providers, merely because they condemn abortion.

Such thinking seems to take mere moral or religious disagreements and elevate them to the level of impermissible speech. The reasoning seems to be that certain moral or religious judgments have been associated with hateful, violent, or discriminatory actions in the past, so such judgments must now be abandoned to avoid such abuses. I see four problems with this reasoning.

First, moral and religious disagreement is an irreducible aspect of the human condition. Such disagreements are not going to end anytime soon.

Second, the problem is not the mere fact of disagreement but the way the conflicting positions are expressed. One can express a principled opposition to homosexual activity, for example, using language that is restrained, respectful, and non-abusive, or one can express it in abusive or hateful ways. The latter is wrong; the former is not. We should focus on educating people to express their differing moral and religious beliefs in language that is as fair and as respectful and as courteous as possible. But surely it is utopian to tell them to stop disagreeing at all.

Third, the range of beliefs that have been associated with violent, abusive, or intolerant behavior is huge. Atheism was part of the official ideology of Communist countries that brutally persecuted religious believers for decades. Should we tell atheists to abandon atheism because of the crimes of some other atheists? Adolf Hitler and the Nazis incorporated Darwinian evolutionary theory and Mendelian genetic theory into their racist ideology. Should we tell biologists to stop teaching these theories because they have been associated with a violent and repressive political movement? The language of universal human rights was an integral part of the French Revolution, which led to the Reign of Terror and the imperialism and tyranny of Napoleon. Should we abandon any talk of universal human rights for this reason?

Fourthly and finally, there is a self-referential logical problem with telling people to abandon moral or religious positions that have been associated with violence or intolerance or discrimination. Not long ago a gay-rights-activist shot a security guard at the office of an anti-gay-marriage organization in a Washington DC suburb of Virginia. If moral opposition to gay marriage or gay sex is wrong because it has been associated with violence against gays in some times and places, must we now say that a pro-gay-rights position is wrong for the same reason? Is everyone thus morally obliged simply to stop talking about gay marriage, the moral status of gay sex, or the dangers of homophobia? This is a reductio ad absurdum of the failure to distinguish between mere moral or religious disagreement, on the one hand, and truly hateful speech, on the other.