A philosophical viewpoint that opinions or beliefs of reality should be based on science, logic and reason. Ideas should not be derived from religion, authority, governments or dogmas.
A free thinker should not reject nor accept any proposed truths of organized religion, established norms, media, etc. They should determine if the belief is valid based on their own knowledge, intuition, research and reason. Just because other people believe in it, doesn't mean it's right! Use your own judgment and think critically!