Positioning disability justice as a force that shapes the broader political imaginary, this article assesses the usefulness of Julia Kristeva's disability theory for disability justice movements. Kristeva advances a theory of dynamic and transformative "interaction" with different embodiment as the basis for a cultural revolution based on the recognition of the singularity of vulnerability. This article elaborates interaction theory in terms of Kristeva's "speaking subject," and clarifies some key psychoanalytic terms that she employs. The timely importance of connecting disability to other political movements and ethico-political discourses is drawn out, by situating it in the context of Jean Luc Nancy's concept of singularity and the Levinasian ethics of alterity. These approaches are synthesized to elicit an ethical politics and critique of neoliberalism that responds to heterogeneous embodiment. The resulting theoretical framework of singularity and ethical difference can be applied in very concrete ways to explore how we might think activist programmes and policy measures differently by shifting from the logic of assimilation to a logic of transformation—that is, from inclusion to interaction.