In this position paper, we review the practice of differentiation -- a universal concept aimed to support diverse students in our classrooms. In exposing the wide-ranging practices of differentiated instruction, and critiques of current implementation, we argue that differentiation in the mathematics classroom needs to be reframed in terms of a social justice perspective. In doing so, we argue that differentiation practices need to move from a focus on cognitive achievement/performance outcomes that serve to divide/label students towards a focus on student well-being and productive mathematical disposition.