What counts as phenomenological? A “thick” phenomenological note on altered states of consciousness classification

This commentary examines Cardeña et al.’s (2025) consensus taxonomy of altered states of consciousness by highlighting a tension internal to their phenomenological commitments. On the one hand, they adopt a “thin” phenomenology, using qualitative methods to collect experience-based data and thereby granting experience an epistemic role. On the other hand, the taxonomic labels under which these data are organized (e.g., identity, self, agency, delirium) draw much of their theoretical content from diagnostic, neuroscientific, and psychological practices that index categories via third-person behavioral and functional markers. I suggest that, while this partial lack of explicit phenomenological grounding is understandable given the article’s aims, making the experiential significance of these labels more transparent could improve the taxonomic project itself. To this end, I propose integrating a “thick,” theoretically articulated phenomenology that treats such labels as experiential kinds, and I use delirium as an illustrative case to show how phenomenological profiles and subprofiles might support richer and more fine-grained altered states of consciousness taxonomies