Racism, sexism, and other forms of systemic injustice are more than just bad attitudes. In a stratified society, there are mechanisms – including law, policy, culture, technology, and the built environment – that stably position groups hierarchically. But attitudes play a role. How central is that role? In this lecture I argue that social practices are patterns of interaction guided by social meanings that distribute things of value. In the case of unjust practices the network of meanings is ideological and is internalized in habits of mind that distort, obscure, and occlude important facts and result in a failure to recognize the interests of subordinated groups. How do we disrupt such practices to achieve greater justice? I argue that resistance to systemic injustice requires us to do more than just challenge false beliefs; social movements change the material and cultural conditions of agency.