In light of the limitations of dominant psychiatric classification systems such as the Diagnostic and Statistical Manual of Mental Disorders (DSM), this special section positions fine-grained clinical phenomena as key to the future of psychopathology research. This shift is necessary given the constraints DSM-based diagnoses place on (a) the specificity of theories and models of psychopathology and (b) efforts to develop alternative paradigms. Fine-grained clinical phenomena offer comparative advantages, but transitioning to their study involves significant challenges. Chief among these challenges is the need to move beyond DSM as a source of concepts. Implicit assumptions that DSM-based disorders provide valid, circumscribed, and explanatory definitions of clinical phenomena perpetuate existing reification of diagnostic categories rather than reimagining psychopathology nosology beyond DSM, thus needlessly restricting and even undermining research efforts. Moving forward requires careful attention to consensual operationalization. Otherwise, we will continue to struggle to develop valid compositional explanations of clinical phenomena and to organize them into explanatory conceptual taxonomies. Scientific progress here depends on coordinated pluralism that incorporates different lenses into psychopathology and different approaches to data collection and analysis, with a firm grounding in construct validity and a corresponding commitment to continually reimagine rather than reify our concepts and objects of study. (PsycInfo Database Record (c) 2023 APA, all rights reserved).