What was the foundation of European thought that Galileo's work challenged?

Answer

The Ptolemaic system.

The resistance centered on overturning the Ptolemaic system, the dominant cosmic model inherited from Aristotle and Ptolemy, which placed the Earth at the center of the universe (geocentrism).

What was the foundation of European thought that Galileo's work challenged?
GalileoastronomytheoryConflictheliocentrism