Read the paired passages. Passage A: Conservators of a damaged theater reconstructed missing decorative panels where photographs, measured drawings, and surviving fragments agreed. In areas with little evidence, they left neutral surfaces rather than inventing ornament. Their aim was to recover the legibility of the interior while marking uncertainty. Passage B: At a ruined fort, conservators stabilized broken walls but did not rebuild the missing upper stories. Because no reliable drawings survived and the ruin itself documented later conflict, reconstruction would have replaced one historical layer with conjecture. Their aim was to preserve the site's accumulated record. What shared conservation principle explains the different intervention levels at the theater and fort?