Objectives <p>To examine how contemporary mindfulness has been transformed through its integration into healthcare, education, and institutional settings, and to clarify what is at stake when contemplative practices are reframed as instrumental techniques.</p> Methods <p>The paper combines conceptual analysis with an illustrative case study of the My Resilience in Adolescence (MYRIAD) trial. Dōgen’s account of practice-realization unity (<i>shushō-ittō</i>) is used as a philosophical lens to analyze the consequences of separating mindfulness practice from its ontological foundations.</p> Results <p>Contemporary mindfulness is argued to exhibit “ontological attenuation”—a reduction in experiential depth arising from its instrumentalization. This attenuation is evident across research design, pedagogical delivery, and participant experience, and reflects structural constraints within secular, institutional contexts.</p> Conclusions <p>Secular mindfulness retains clinical and practical value but does not reproduce the ontological commitments of its contemplative sources. Greater conceptual and ethical clarity is needed, including explicit recognition of what mindfulness can and cannot deliver within modern contexts.</p>