Dialectical pluralism is both a philosophical process theory and grounded approach for producing syntheses from differences, working toward mutually beneficial solutions, and, through group processes, produces procedural/process justice in mixed methods research and evaluation. Ontologically, dialectical pluralism views reality as plural and changing. Epistemologically, it follows a dialectical, dialogical, hermeneutical approach that includes listening, interacting, and learning from the Other. After explaining how the philosophical process theory of dialectical pluralism provides a process for positively and systematically engaging with differences, we draw on concepts and findings from social psychological literatures such as positive psychology, conflict management, negotiation, small group psychology, group counseling, group dynamics, political diplomacy, deliberative democracy, and workplace justice to show how dialectical pluralism enables learning from differences and produces effective collaboration across paradigms. Implementation strategies are identified for integrating DP into mixed methods research and evaluation (MMR/E). We conclude with a brief vision for MMR/E driven by the philosophy of DP that we hope will be attractive to a wide range of practitioners working across different contexts and topics.