The teaching profession's present notion of the ability of teachers to contribute to theory development in language education needs reexamination. University researchers can best foster this ability by encouraging and assisting teachers to become engaged in classroom research. On the basis of both published evidence and field data, it can be argued that (1) teachers inescapably function as theorists, (2) their potential contributions to theory are vital to the growth of the profession, and (3) their work as theory builders is enhanced by engaging in the process of research. Current literature as well as examples from field work with researchers who teach in public school classrooms show that research enhances theory building by helping teachers focus observations, sharpen research skill, and develop collegial relationships with other researchers and theorists. Finally, many current notions of teacher research are too limited to be useful in theory building. The vital contributions of teachers to language learning theory will come through their involvement in what James Britton called "basic research." Inviting teachers, who live daily with the complex realities of language growth through language use, to be full partners in the enterprise of research and theory development is the "best help" for teachers, and the teaching profession as well. Teacher researchers can provide theoretical enrichment as thoughtful professionals constantly in touch with crucial data. (Fifty references are attached.) (RAE)