Poppers three worlds and attitudes to the explanatory gap

The thesis is explored that Poppers three worlds may be used as an intuition pump to reveal the insight that all three attitudes to the explanatory gap (that there is no gap, an unclosable gap, or a closable gap) are true from different perspectives. Ontologically, there is only one world and no gap. Epistemically, there is an irresolvable duality, an unclosable gap. From the point of view of scientific theory, there is a soluble problem, that of providing a principled account of the relation between phenomenal features of consciousness and functional accounts in terms of behaviour, neurophysiology and physics. Requirements for filling the gap are examined in more detail, and attempts to fill the gap are discussed. It is argued that, on current knowledge, it appears that only at tlie level of sub-atomic physics can parallels with phenomenal features of consciousness be found that are sufficiently powerful to provide a transparent account.