Economic and political power alone is no longer sufficient in solving such complex 21st century problems as poverty, climate change, and securing the peace. However, Social Justice and Deep Participation offers the means to change this status quo. Deep participation allows institutions to be collectively reorganized within their own culture at both community and international levels. In contrast to ordinary participation, it operates only in the context of rapid social change and instability, but is available to every society. Key elements that contribute to institutional legitimacy encompass inclusion and mutual social learning which in turn contribute to group acts of altruism. It is not just one more ideology. Rather, deep participation accesses social integrative power, similar to the much better recognized 'political threat power' and 'economic coercive power'. It provides new approaches to hands-on-change and lays out an emerging participatory social theory which promises a greater prosperity and justice for all.