In this article I explore epistemological diversity in the field of second language acquisition (SLA) from the perspective that obtains if we examine the moral ends of research, and we ask: In what ways does epistemological diversity relate to enhancing the social value and educational relevance of the research generated by the instructed SLA research community? Is epistemological diversity sufficient in order to produce high-quality SLA research that positively impacts on society and education? Through several illustrations, I show that epistemological diversity is a disciplinary reality that is here to stay and, furthermore, that it is a good thing. At the same time, I argue that it is insufficient in and of itself. Instead, I propose that it is crucial to interrogate the moral ends of our research and to probe the social value and educational relevance of what we choose to investigate and of the knowledge we generate.