The consistency strength ordering places one mathematical theory below another if the first theory cannot prove the second is consistent but the second can prove the first is consistent. Researchers have long observed that natural theories arising in set theory and proof theory seem to line up in a single linear hierarchy under this ordering, but it remains unproven whether this linearity holds universally for all natural extensions of ZFC, and whether the resulting order is actually well-founded with a classifiable ordinal length. The paper on bar induction establishes linearity within a specific bounded region between ACA_0 and BI using reflection calculi, and the ZFC extension paper constructs a canonical inevitable extension, each contributing local evidence, but no global structural theorem exists.