Although the overall mission of second language (L2) teacher education has remained relatively constant, that is, to prepare L2 teachers to do the work of this profession, the field's understanding of that work—of who teaches English, who learns English and why, of the sociopolitical and socioeconomic contexts in which English is taught, and of the varieties of English that are being taught and used around the world—has changed dramatically over the past 40 years. This article examines the epistemological underpinnings of a more general sociocultural turn in the human sciences and the impact that this turn has had on the field's understanding of how L2 teachers learn to do their work. Four interrelated challenges that have come to the forefront as a result of this turn are discussed: (a) theory/practice versus praxis, (b) the legitimacy of teachers' ways of knowing, (c) redrawing the boundaries of professional development, and (d) “located” L2 teacher education. In addressing these challenges, the intellectual tools of inquiry are positioned as critical if L2 teacher education is to sustain a teaching force of transformative intellectuals who can navigate their professional worlds in ways that enable them to create educationally sound, contextually appropriate, and socially equitable learning opportunities for the students they teach.