MLU: Perhaps before delving into those specifics--for the benefit of readers who may not be familiar with your work with the Pirahã--can you set the stage for our discussion? What was your purpose for going to the Amazon Basin, how long were you there, and what did you accomplish?
DE: In 1968 at the age of 17, I became a Christian, mainly through the friendship of some missionaries I met in San Diego. They had worked in the Brazilian Amazon since the early 1950s and told me all about their work and their plans for returning. It sounded like the most exciting work imaginable. So I quit my (very good) rock band and began a new life as a Christian missionary in training. Since I married these missionaries' daughter at the age of 18, there was a lot of schooling and work along the way. By 1976, I was a graduate of the Moody Bible Institute of Chicago, with a diploma in Foreign Missions, and a member of Wycliffe Bible Translators. Since I had done well in my missionary training, including some linguistics, and because we were interested in Brazil, the mission asked us if we'd consider working among the Pirahã people. Their language was supposed to be very hard and very unlike any other language in the Amazon. Two Wycliffe missionary teams had worked with the Pirahãs, beginning in 1959, but no one had made any significant progress on understanding the grammar of the language. But just as we arrived in Brazil in October of 1977, ready to take up the challenge of the Pirahã language the Brazilian government prohibited missionaries from working in tribal societies. To fill up the time until the government might reconsider its decision, the mission asked me to consider trying to get into a graduate program in Linguistics in Brazil. I was accepted into Brazil's number one linguistics program of that time, at the University of Campinas in Sao Paulo (UNICAMP) and began my training as a professional linguist. In the next three decades, I finished a PhD in Linguistics from UNICAMP, spent a year as a Visiting Scientist at MIT's Department of Linguistics and Philosophy, with an office next to Noam Chomsky's, completed the translation of the Gospel of Mark into Pirahã (a professionally recorded version of which is available on my website), published nearly 100 articles and six books in linguistics, and abandoned my faith, through the example of the Pirahãs. I lived for over 7 years with the Pirahãs, in all of their villages. In addition, I have conducted research on and published on over a dozen other Amazonian languages. Eventually, I took at position at the University of Pittsburgh, as Chairman of Linguistics, for about 10 years. After that, I gave missions another try. But I realized that I could neither save my missionary zeal nor my marriage, so I went public with my lack of faith and lack of interest in missionary work and accepted a position of Professor of Phonetics and Phonology at the University of Manchester.
MLU: You have had a fascinating life, and I think your extensive field experience goes a long way toward validating the controversial conclusions you reached regarding the nature of human language. What impresses me is that you began your career with one set of beliefs, and wound up with quite another. You did not set out to contradict Chomsky's theory of universal grammar, for instance--at first you endorsed his ideas and even taught them to others in a University setting. And you did not set out to lose your religious faith, either; you began as a believer. Yet the fact that these changes did occur--in spite of your initial inclinations--tells me that you are a deep and evidence-based thinker. Your conclusions are hard won.
Please explain Chomsky's theory of universal grammar for us. Why it has been considered so important, and how and why did your work with the Pirahã lead you to conclude that Chomsky's theory is incorrect?