What has happened in the last generation is that Tijuana has become a new Third World capital - much to the chagrin of Mexico City, which is more and more aware of how little it controls Tijuana politically and culturally. In addition to whorehouses and discos, Tijuana now has Korean factories and Japanese industrialists and Central American refugees, and a new Mexican bourgeoisie that takes its lessons from cable television.

The genius of American culture and its integrity comes from fidelity to the light. Plain as day, we say. Happy as the day is long. Early to bed, early to rise. American virtues are daylight virtues: honesty, integrity, plain speech. We say yes when we mean yes and no when we mean no, and all else comes from the evil one. America presumes innocence and even the right to happiness.

Mexico is sex and Canada is mind. There is much about Canada that I find admirable - the treatment of immigrants, for example, particularly those from Central America during the recent civil wars there. But there is confusion too: I know of Croatian Nazis who are subsidized by the Canadian government to maintain their racist culture. There is Canada, trying to sustain diversity without knowing exactly what it's doing.

The first book by an African American I read was Carl T. Rowan's memoir, Go South to Sorrow. I found it on the bookshelf at the back of my fifth-grade classroom, an adult book. I can remember the quality of the morning on which I read. It was a sunlit morning in January, a Saturday morning, cold, high, empty. I sat in a rectangle of sunlight, near the grate of the floor heater in the yellow bedroom. And as I read, I became aware of warmth and comfort and optimism. I was made aware of my comfort by the knowledge that others were not, are not, comforted. Carl Rowan at my age was not comforted.

America has never had a very wide vocabulary for miscegenation. We say we like diversity, but we don't like the idea that our Hispanic neighbor is going to marry our daughter. America has nothing like the Spanish vocabulary for miscegenation. Mulatto, mestizo, Creole - these Spanish and French terms suggest, by their use, that miscegenation is a fact of life. America has only black and white. In eighteenth-century America, if you had any drop of African blood in you, you were black.

Of course, San Diego chooses not to regard the two cities as one. Talk about alter ego: Tijuana was created by the lust of San Diego. Everything that was illegal in San Diego was permitted in Tijuana. When boxing was illegal in San Diego, there were boxing matches in Tijuana; when gambling was illegal, there was always Tijuana.

When the Irish nun said to me, "Speak your name loud and clear so that all the boys and girls can hear you," she was asking me to use language publicly, with strangers. That's the appropriate instruction for a teacher to give. If she were to say to me, "We are going to speak now in Spanish, just like you do at home. You can whisper anything you want to me, and I am going to call you by a nickname, just like your mother does," that would be inappropriate. Intimacy is not what classrooms are about.