The overarching project of the conceptual and empirical contributions in this special issue is to redraw boundaries for language teacher cognition research. Our aim in this final article is to complement the foregoing collection of articles by conceptualizing ontologically and methodologically past and current trajectories in language teacher cognition research and synthesizing various themes that arise across this body of work. To that end, we begin by first making the case for the construct under examination and posing some key questions: What is the nature of the mind that we are examining in language teacher cognition research? How have conceptualizations of that mind changed over the period that language teacher cognition research has emerged as a field of empirical study? We then consider how the mind in language teacher cognition research has been studied ontologically, and the conceptual advances that have characterized such research. We conclude by examining how studies in this collection reflect our account of these changes over time.