In this special issue, the structure-agency dialectic is used to shift the analytic frame in science education from focusing on youth as in need of remediation to rethinking new arrangements, tools, and forms of assistance and participation in support of youth learning science. This shift from "fixing" the individual to re-mediating and transforming the functional system is key to reimagining new forms of learning and doing science that are tied to the imaginings of new futures, trajectories, and identities. In this manuscript, we discuss the major contributions of these studies in the special issue. In so doing, we seek to lay out both the possibilities and limits of the structure-agency dialectic in advancing science for all. We suggest that social and pedagogical imaginaries enable one to move the structure-agency dialectic towards transformative ends. We further suggest that to account more actively for how position and power shape the ways in which individuals seek to take action, the meanings they ascribe to such action, symbolically and otherwise, we must be ready to interrogate the relation between structure and agency and issues of equity and consequential and valued forms of science learning in local environments and in larger educational systems.