Abstract The Where Science Ends (WSE) framework defines a two-axis space — structural eliminability and strong falsifiability — within which any claim about consciousness must be located. This paper applies four WSE-derived criteria to twelve major theories of consciousness and finds that no existing theory satisfies all four simultaneously. More than a negative result about individual theories, this reveals a structural incompatibility: any theory that formally locates the hard problem in Cell IV (criterion C4) cannot treat its phenomenal postulate as structurally eliminable (criterion C1), and vice versa. This incompatibility is not a defect of current theories — it is a theorem about the structure of the problem. Even Perspectival Structural Realism (PSR), designed specifically to operate within the WSE framework, cannot pass all four criteria and does not claim to. The second half of the paper argues that the goal of an exhaustive theory of consciousness should be distinguished from the goal of an engineering theory for building a conscious artificial system. An engineering theory requires a different and less restrictive configuration of criteria: sufficient structural conditions (C1), partial falsifiability (C2-partial), coherence (C3), and explicit acceptance of the constitutive bridge as a pragmatic commitment rather than a scientific claim (C4-engineering). We propose PSR-E, an engineering extension of PSR that satisfies this configuration, and assess which existing theories come closest to meeting engineering requirements and what they lack. Keywords: theories of consciousness; hard problem; structural eliminability; falsifiability; Where Science Ends; engineering theory of consciousness; artificial consciousness; Perspectival Structural Realism; Cell IV.
Alastair Waterman (Mon,) studied this question.