Richard King challenges the modern, psychologised notion of mysticism, which has often shielded philosophy from engaging with a long, rigorous and diverse tradition of apophatic critique.

In this study, rather than treating apophasis as an ineffable feeling, King presents it as a sustained philosophical argument. He explores its core strategies, including dismantling concepts, questioning representational language and loosening the grip of possessive subjectivity, across three major traditions: Western negative thought, Advaita Vedanta and Indian Mahayana.

These traditions, read comparatively yet on their own terms, reveal convergent strategies that unsettle ontological assumptions about substance, self, and ultimacy while expanding the repertoire of what counts as philosophical reasoning. The result is a direct challenge to modern boundary-work that isolates 'mysticism' from philosophy. By relocating apophasis at the centre of philosophical inquiry, King proposes a broader, cross-cultural history of philosophy in which arguments about non-duality, emptiness, ethics, and the limits of concept and will are not marginal curiosities but canonical problems.

This reframing calls for revisions to curricula, to the philosophy–theology divide, and to the analytic/continental map, while opening new lines of debate in metaphysics, epistemology, and moral psychology.