Passage Summary: Even though both Copernicus and Ptolemy had theories that matched the evidence of their time, Copernicus's idea was better because it was simpler; he realized it was more likely that the Earth rotates than that the stars move at impossible speeds.

Conclusion: Copernicus's astronomical system was superior to Ptolemy's at the time it was proposed.

Reasoning: While both theories were equally consistent with the observational evidence available at the time, Copernicus's theory was simpler than Ptolemy's.

Analysis: The core of this argument is a classic appeal to 'Occam's Razor'—the idea that simplicity is a virtue in scientific theories. The author establishes a situation where two competing theories are empirically equivalent and then uses the relative simplicity of one to declare it superior. To find the matching principle, you should look for a rule that prioritizes simplicity as a deciding factor for the quality of a theory when observational data cannot distinguish between them. It is not necessarily about which theory is 'true' in an absolute sense, but rather which one is 'better' based on its lack of unnecessary complexity.