Conversion Theory unveils qualia via process dualism: Brain-computer interfaces reach limits as objective data irreversibly converts to inaccessible private phenomenology.

Qualia the vivid hues of subjective experience emerge from an irreversible neural alchemy. Objective sensory data streams into the brain, where amygdala and hippocampus forge it into private phenomenology through profound process dualism. Brain-computer interfaces capture upstream signals with stunning precision yet hit an »epistemic firewall«: the downstream qualia remain sealed, their essence lost in conversion. Karl Johannes Lierfeld analyzes this physicalist extension that reveals why sentience defies objectification, bridging philosophy of mind and neuroscience without metaphysical escape hatches. Conversionism charts the hard problem's structural limits.

Autorentext
Karl Johannes Lierfeld (Dr.), born in 1977, transitioned from being a screenwriter to an author of non-fiction books about AI, ethics, and deep tech. Additionally he is a researcher and entrepreneur, bridging inner and outer space (neuroscience and spacetech). With his start-up HABITATO he founded a dual-use 3D printing enterprise for terrestric and exraterrestric applications. In 2025, HABITATO´s spacetech division LUNAR HABITATO obtained three design IPs and became industrial partner for an ESA/Fraunhofer research project about lunar digital twins as well as a swarm robotics study by Polytecnico Turino and MIT Media Lab. 2026 he defended his second dissertation at Ludwig- Maximilians-Universität München at the Institute of Philosophy of Mind.