TWO HEADS.(Patricia Churchland, Paul Churchland )(Biography)

It's a little before six in the morning and quite cold on the beach. It's low tide, and the sand is wet and hard-packed and stony. This early on a Sunday, there are often only two people here, on the California coast just north of San Diego. Patricia Churchland is throwing a rubber ball into the ocean for her two dogs (Fergus and Maxwell, golden retrievers) to fetch. Her husband, Paul Churchland, is standing next to her. They are both wearing heavy sweaters. They are in their early sixties. They are tall--she is five feet eight, he is six feet five. They come here every Sunday at dawn.

Pat is constantly in motion, throwing the ball, stepping backward, rubbing her hands together, walking forward in a vigorous, twitchy way. She has pale eyes, a sharp chin, and the crisp, alert look of someone who likes being outside in the cold. (Even when it is sunny, she looks as though she were enjoying a bracing wind.) She seems younger than she is: she has the anxious vitality of a person driven to prove herself--the first to jump off a bridge into freezing water. Paul stands heavily, his hands in his pockets. He is still. He nudges at a stone with his foot. He looks up and smiles at his wife's back. He has a thick beard. He looks like the sort of person who finds it soothing to chop his own wood (and in fact he is that sort of person).

Paul and Pat met when she was nineteen and he was twenty, and they have been married for almost forty years. They are both Canadian; she grew up on a farm in the Okanagan Valley, he, in Vancouver. They have two children and four grandchildren. They live in Solana Beach, in a nineteen-sixties house with a small pool and a hot tub and an herb garden. Each summer, they migrate north to a tiny island off the Vancouver coast. Both are professors of philosophy at the University of California at San Diego. They have been talking about philosophy together since they met, which is to say more or less since either of them encountered the subject. They test ideas on each other; they criticize each other's work. At this point, they have shaped each other so profoundly and their ideas are so intertwined that it is impossible, even for them, to say where one ends and the other begins. Their work is so similar that they are sometimes discussed, in journals and books, as one person. Some of their theories are quite radical, and at the start of their careers the Churchlands were not always taken seriously: sometimes their ideas were thought silly, sometimes repugnant, verging on immoral. In those days, they formed a habit of thinking of themselves as isolates aligned against a hostile world, and although they are now both well established in their field, the habit lingers.

"For the first twenty-five years of our career, Pat and I wrote only one paper together," Paul says, "partly because we wanted to avoid--"

"We wrote more than that," Pat says.