Which theoretical and empirical insights can inform language-in-education research that advances equitable and high-quality learning at school? In this three-part article, I first draw from various sources to foreground the urgent need to counteract linguicism and epistemic injustices and to commit to more just and rigorous scientific practices in research and education. Based on findings from my own research, I then argue that more just and rigorous practices need to attend to midadolescents' individual differences in language learning. In response, I present insights from recent innovative evidence-based pedagogical frameworks and tools that reveal promising paths forward. I close by calling for research with a dual focus on equity and rigor that supports moving away from "pedagogies of silence," which silence marginalized students' voices, damaging their identities and obstructing their learning, towards "pedagogies of voices," which affirm all learners' voices while amplifying their language repertoires and their critical learning. [This is the online version of an article published in "Language Learning" (ISSN 0023-8333).]