Cochlear implants, which work best with children, are viewed as an example of intolerance and aggression that remove deaf children from their culture, just as missionaries once took Indian children from their tribes and put them in Christian boarding schools. In "Sound and Fury," a deaf Long Island couple refuse to let their 5-year-old daughter get a cochlear implant. The father has a lament: "If the technology progresses, maybe it's true that deaf people will become extinct, and my heart will be broken."

This is a poignant moment. The parents know that if they approve the implant, they will lose their daughter to a wider world they can never enter (and don't want to enter). The daughter would go to a hearing school and have hearing friends, to the probable exclusion of her family. But the plain fact is that the parents are preventing a cure for deafness for ideological reasons. An upside-down logic is at work here: helping a girl to hear is an attack on her and her culture, as many voices in the film keep insisting.

As columnist Cathy Young writes in Reason magazine, this is an example of how "the celebration of difference and pluralism has brought modern western culture to the brink of lunacy." In the movie, the father talks of how "peaceful" it is to live in a world of total silence. This defense mechanism, Young says, is shockingly treated as a serious argument these days, particularly among the intellectual elites. Once deaf people are defined as a cultural group, not inferior to hearing culture, then any move by hearing people to correct deafness is illegitimate. This follows from the belief, now widely held in the academic world, that all cultures and all arguments are equal.

In his book "The Mask of Benevolence," Northeastern University psychologist Harlan Lane lays out the argument that American deaf people have been oppressed and "colonized" like Third World countries taken over by European powers. There is a great deal of talk about "the medicalization of cultural deafness" and the blundering "audist establishment" (the hearers). This kind of thinking earned him a MacArthur Foundation "genius" award, proving once again that if you wish to become a MacArthur version of a genius, bizarre multicultural ideas can be quite helpful.

The view of deaf people as "a linguistic and cultural minority with a rich and unique heritage" (Lane's words) has made great headway in academic circles and the media. Deaf people have many institutions that parallel mainstream ones, from deaf basketball leagues to a Miss Deaf America contest.

Disability in general is increasingly seen as a culture worthy of study and respect. Disabilities studies are sweeping through the academic world, and universities are starting to compete for disabled professors. Some of the study programs look like an attempt to establish a political beachhead on the campuses, as was done by the creation of women's studies and black studies. A new online Disability History Museum (one that "taps hot issues," says a Boston Globe editorial) celebrates the achievements of disabled Americans. The museum will provide a disabilities curriculum for children in grades 5-12. Exactly why the nation's students, currently caught up in the back-to-basics movement, should study disability for eight years is obscure.

Though obesity is rarely thought of as a disability, the size-acceptance movement uses the same logic as the disabilities movement. Dieting, or trying to reduce a child's weight, is positioned as an illegitimate attack on the differently sized. Words such as "overweight" and "fit" are often put in quotation marks to isolate them as terms used by intolerant outsiders who want to impose their own standards and the idea that stoutness is a problem.

Disability activism, alas, has given itself over to identity politics. As the late critic Christopher Lasch wrote, the politics of group identity is therapeutic in origin and functions like a group of dogmatic religions "in which rival minorities take shelter behind a set of beliefs impervious to rational discussion." Like rational discussion about cochlear implants, for example.