noun
freethinker
Refers to a person who forms opinions independently of authority or tradition, especially in religious or philosophical matters.
彼は自由思想家として知られ、既成の宗教に縛られなかった。
He was known as a freethinker and was not bound by established religion.
Compound of 自由 (freedom) + 思想 (thought) + 家 (person). The term is a direct calque of English 'freethinker'.