What do you call a person who challenges widely accepted ideas they consider incorrect or foolish?

Explanation

A philistine is someone who is indifferent or hostile to culture and intellectual pursuits, often criticizing popular beliefs they find misguided. An iconoclast challenges established traditions or beliefs, but the term does not fit the description as closely as philistine in this context. An imposter is a deceiver, and a cannibal consumes human flesh, which are unrelated to the question.